Aiming at the problem of mission assignment and interception guidance for multiple targets in space，based on the adaptive guidance law of head-on and head-pursuit interception mode, the multi targets assignment strategy of OTPN has been studied, and criteria sequences to assignment was established as the core of interception mission assignment and parameter configuration for interception guidance, and carry out multi-target interception numerical simulation. The simulation results verify the validity of this method, which is simple, flexible, and easy for calculation. The method solved the inadequacy that all interceptors must take the same mode when intercepting multi-targets, and ensuring the maximum interception success rate as well as in giving full play to advantage of head-on and head-pursuit interception mode, and has a flexible adjustment ability also, which can meet the requirements of target assignment and interception effect for multiple to multiple interception.