The results of rock stick-slip dislocation experiments in the laboratory show that one stick-slip dislocation process includes three stages generally:pre-slip stage, stick-slip stage, and stop-slip stage. We found the stick-slip dislocation process is often not a single point stick-slip dislocation process, but is composed of multi-point stick-slip dislocation process, showing the characteristic of multi-point stick-slip dislocation in the different parts of the fault. A strong earthquake of magnitude M_W7.9 occurred at Wenchuan, China, on May 12, 2008. The process of coseismic stick-slip dislocation and stop-slip process of the earthquake were recorded perfectly by the digital seismograph of Global Seismographic Network's (GSN) 74 seismic stations and the deep borehole water level digital instrument of Zhouzhi seismic station, China. After analyzing these recordings, we find that multi point stick-slip dislocation process during the Wenchuan M_W7.9 earthquake. According to the observational evidence, the stick-slip dislocation process may be composed by four sub-stick-slip dislocation events.The duration time of whole process of stick-slip dislocation is more than 86.6 s. We infer to the Wenchuan M_W7.9 earthquake may be a result of elastic rupture and stick-slip dislocation commonly. It is a kind of "stick-slip dislocation + elastic rupture" mechanism. After analyzing the recording of deep borehole water level digital instrument of Zhouzhi seismic station, we find the results of coseismic stick-slip dislocation process of Wenchuan M_W7.9 earthquake are consistent with the rock stick-slip dislocation experimental results of P. N. Sundaram^[1]. The stick-slip dislocation process can be divided into the stick and the slip two process. The stop-slip phase XsQ and XsR are excited during the stop-slip process of Wenchuan M_W7.9 earthquake. The XsQ and XsR phase are Love type surface wave and Rayleigh type surface wave, respectively. The travel time relationships of P+Xs1, Xs2, Xs3, Xs4, XsQ and XsR phases are given, at Δ=5.3°-121.0°. Studying the Xs phase will be helpful for understanding the processes of the stick-slip dislocation. Studying the XsQ and XsR phase will be helpful for judging disaster loss of the great earthquake.