This paper deals with the equilibrium strategies on complementary takeover collusion.Considering the incomplete information of the value on the target and based on the bidding model,we manifest the incentive for collusions and resolve the rational interest compensation,and then get the equilibrium collusion strategies.Furthermore,we analyze the response strategies of the target firm's reservation price.It is shown that the bidding collusion does not erode the economic benefit of takeover,and the target firm can restrain from collusion by setting a reasonable reservation price.