Abstract: This paper focuses on the total aim and research idea of HD-STGPS(Huada super totalstation GPS) and its function character.The related coordinate transformation and GPS service for surveying are discussed.A new surveying mode called "Positioning and Instance Detail Surveying without dense control network" is put forward.This is a great improvement to the traditional large scale detail surveying mode.By this method,we just set up a control network consisting of a few points.The point in this control network will be used as the reference station for GPS.The heavy surveying work of setting up dense control network consisting of many points is exempted.The maintenance work of control points is also greatly reduced as the number of the control points needed is only for the purpose of reference station.This paper emphasizes on how to transfer the WGS84 Cartesian coordinates to the local 2D plane coordinates and the orthometric height by a series of mathematical models.The GPS receiver,totalstation,radio,notebook computer and the corresponding software work together to form the new surveying system.All the data is manipulated through software via interface.The GPS raw measurements at the reference station are broadcast to the rover.The rover consists of a GPS receiver,totalstation,radio and a computer.The raw measurements of the rover are also transmitted to the computer.Then the GPS baseline is solved and the coordinates of the rover are calculated and transferred to local coordinate system.The Totalstation will communicate with the computer and utilize the coordinates got by GPS immediately.For other detail points with bad sky view situations,the signal from the GPS satellite is severely interrupted by buildings or other obstacles around the station,and can not be located by GPS.But they can be measured by Totalstation.STGPS will fully use GPS and Totalstation.If a public GPS service network has been set up in an area,then these points can be used as reference points of the STGPS.With the rapid development of GPS technology,many cities will set up a group of multi-function GPS service stations,which will be very helpful for STGPS.