Abstract: In the environment of frequent technical iterations and rapid economic development, the innovation needs and risks of high-tech enterprise innovation alliance members are gradually increasing, and innovation based on competition and cooperation becomes their only way. Pure competition or cooperation is emphasized by most of the previous studies, but as the new market environment changes, its drawbacks continue to emerge, and the coopetition strategy come into being. Therefore, based on the duality of competition and cooperation demonstrated by the innovation behavior of members of China's high-tech enterprise alliance, this paper aims at the coopetition relationship between members in the high-tech enterprise innovation alliance. From the theoretical perspective of coopetition, the factors affecting the coopetition relationship among the members of the alliance is analyzed. The evolutionary game theory is used to construct the evolutionary game model of the high-tech enterprise innovation alliance member A and B co-opetition relationship. By solving the replication dynamic equations of the ratio of the cooperation strategy between the both sides of the game, the evolutionary path of alliance members' coopetition relationship in the two cases when the synergistic benefit is not enough to make up for the risk cost and when the synergistic benefit is enough to make up for the risk cost are analyzed. And then, the strategic choices of alliance members under the influence of factors such as trust, complementarity, risk factors, and cooperative innovation discount factors are analyzed. Finally, Matlab is used to verify the above factors by numerical simulation. The result reveals that the improvement of the level of collaborative innovation trust makes the opportunistic behavior and vicious competition among the members of the alliance are effectively suppressed, and the stability of the alliance is guaranteed. In addition, the increasing complementarity among members of the alliance helps to establish a close relationship is between members, thereby the stable operation of the alliance is ensured. Moreover, the improvement of the cooperative innovation discount factor can enhance the confidence of the partners in long-term cooperation by reducing the uncertainty of future benefits of alliance members and the stable operation of the alliance is maintained. Finally, since the higher risk factor increases the risk cost of cooperative innovation, the cooperation between alliance members may evolve into a competitive relationship, and the stable development of the alliance is hindered. Based on this, high-tech enterprises should choose suitable partners according to their own situations, and the cooperative relationship with partners is effectively utilized to avoid conflicts and excessive competition. The research conclusions provide theoretical and practical reference for the high-tech enterprise innovation alliance members to effectively choose the coopetition strategy.

Key words: innovation alliance, coopetition, evolutionary game, alliance stability