Taking both synergistic effect and Poisson jump into account,the paper studies the timing of MA using the method of real option and optimal stopping. Through the establishment of the MA model with two players,in which both of the players' value are uncertain but related,and the acquainted player accepts the MA without condition,the paper solves the optimal timing of MA and corresponding region to make decision under the condition where Poisson jump exists and the condition where Poisson jump does not exist. The result shows that the company 1 will obtain more value of waiting option but narrower MA region with Poisson jump comparing with that without Poisson jump.