Aiming at the problem of poor information-level fusion detection and localization accuracy， this paper proposes a multi-platform active-passive radar information-level and signal-level data fusion localization method based on the principle of least squares， and for the existing signal-level fusion algorithms that need the target's a priori information for the temporal alignment of the signal-level fusion algorithms， it puts forward a temporal alignment method based on the positional information of the platform itself and the positional relationship between the platforms. Simulation results show that the method proposed in this paper can effectively realize target positioning. Furthermore， multi-platform active and passive radar signal-level coordination can obtain smaller root mean square error of target positioning and improve the target positioning accuracy relative to the information-level coordination， as well as pure active radar coordination and pure passive radar coordination.