(TD-SCDMA digital trunking system is a development direction of trunking communication system. Firstly, the single call and group call of the trunking communication system are introduced, and the characteristics of switching between these two different communication methods are analyzed; then the traditional switching of the TD-SCDMA system is introduced, and the automatic switching of the TD-SCDMA trunking system according to the moving speed of the mobile station is given. Adapted switching algorithm; finally simple analysis of switching function)