By means of power linkage chart method, the model of closed loop pumping system of concrete pump was set up and simulation was carried out in the Matlab. The results show that the hydraulic shock in the closed loop did not occur at the rapid commutation of piston pump and it actually happened when the concrete was pushed forward after compression. The main piston pump commutation is soft action and this shock can be eliminated effectively by means of “SN” control. Closed loop delivery system is used more widely in high volume concrete pumps and is featured by advantages like energy saving, smooth commutation and low hydraulic shock. In this paper, by means of power linkage chart method, the model of the system was set up and dynamics equations set of the system was obtained. A simulation model was set up by means of simulation toolkit in Matlab language – Simulink, in order to have simulation study of commutation shock of the pumping system and shock due to pushing load and obtain the transient performance of model in time domain.