Recursive implementation feels like you still need to use an accumulative variable as a marker to terminate sending the request, which is similar to the reason for the loop you write

if (res) {
  var j = 0
  function request (){
    mui.ajax('http://XXXXX', {
     data: {
       tugwork_s_id: net[j].TUGWORK_S_ID,
       IsMooring: net[j].If_mooring,
       IsPickup: net[j].ISPICKUP,
       godate: net[j].Godate,
       startdate: net[j].Startdate,
       enddate: net[j].Enddate,
       backdate: net[j].Backdate
     },
       dataType: 'json',
       type: 'post', 
       timeout: 5000, 
       success: function(res) {
         console.log(JSON.stringify(res));
       },
       error: function(xhr, type, errorThrown) {
         console.log('Update_local');
       }
    });
    jPP
    if (j < net.length) {
      request ()
    }  
  }
  // 
  request ()

}

solved the difficulty of writing my own
, which is more complicated than I thought.

function onNetChange() {
            var nt = plus.networkinfo.getCurrentType();
            if (nt == "2" || nt == "3" || nt == "5" || nt == "6") {
                mui.toast("");
                plus.device.vibrate();
                s = plus.audio.createPlayer("../audio/NetYes.mp3");
                var num = s.getDuration(); //number 
                setTimeout(function() { // 
                    var num = s.getDuration();
                    // alert(num)
                }, 100)

                s.play(function() { // 
                    // alert("Audio play success!");
                }, function(e) { // 
                    // alert("Audio play error: " + e.message);
                });
                var tx = db.transaction("users", READ_WRITE);
                var store = tx.objectStore("users");
                var index = store.index("Ifnet");
                var req = index.openCursor(IDBKeyRange.only("1"));
                var odiv = document.getElementById("tijiao");
                if (odiv.style.display = "none") {
                    odiv.style.display = "block";
                } 
                req.onsuccess = function(evt) {
                    var res = evt.target.result;
                    if (res) {
                        var net = [res.value]
                        var j = 0;
                        function submit(){
                            if(j>=net.length){ 
                               return;
                            }
                            mui.ajax('http://', {
                                data: {
                                    tugwork_s_id: net[j].TUGWORK_S_ID,
                                    IsMooring: net[j].If_mooring,
                                    IsPickup: net[j].ISPICKUP,
                                    godate: net[j].Godate,
                                    startdate: net[j].Startdate,
                                    enddate: net[j].Enddate,
                                    backdate: net[j].Backdate
                                },
                                dataType: 'json', //json
                                type: 'post', //HTTP
                                timeout: 5000, //10;
                                success: function(req) {
                                    console.log(JSON.stringify(req));
                                    jPP;
                                    submit();
                                },
                                error: function(xhr, type, errorThrown) {
                                    console.log('Update_local');
                                }
                            });                                
                        }
                        submit();
                        res.continue();
                    }
                };
                req.onerror = function(evt) {
                    console.error("UpData error:", evt.target.errorCode || evt.target.error);
                };
                setTimeout(function(){odiv.style.display = "none";}, 3000);                                        
            } else {
                mui.toast("");
                plus.device.vibrate();
                s = plus.audio.createPlayer("../audio/NetNo.mp3");
                var num = s.getDuration(); //number 
                setTimeout(function() { // 
                    var num = s.getDuration();
                    // alert(num)
                }, 100)

                s.play(function() { // 
                    // alert("Audio play success!");
                }, function(e) { // 
                    // alert("Audio play error: " + e.message);
                });
            }
        }