In the process of multi-beams pulse laser synthesis, the synchronization time delay control precision and the pulse width control precision have important influence on the final distribution of the superposition beam energy. Based on the beam superposition theory, four beam pulsed laser light energy superposition model was established. Four beam shaping pulse as the incident light source, respectively, the superposition pulse energy distribution was calculated by the synchronization time delay control precision and the pulse width control precision. The results show that, with the decrease of the synchronization control precision and the pulse width control precision, pulse width of the superimposed pulse increase and the peak intensity reduce. The multi-beam beams will have greater influence on synthesis beam than single beam. In four laser synthesis system, when other pulse parameters remain unchanged and if the laser pulse peak intensity change rate is less than 5%, the single beam laser pulse time delay and pulse width change rate are kept within 3.2% and 10.9%. Therefore, the effect of pulse time delay on the synthesis intensity is even greater.