In order to recover the projectile borne recorder, it is necessary to accurately find the position of the projectile impact point, and ensure that it can still accurately find the location of the impact point when the impact point is in the shielding environment and poor wireless transmission environment. A multi positioning beacon machine is designed. Firstly, the target position is reduced by using the final received GPS positioning signal, and then the projectile impact point is found by detecting the target signal strength. This design is composed of GPS module of transmitter, decoding module controlled by FPGA, Lora remote wireless module, data processing and display module of receiver, directional antenna, etc. The experiment is a fixed-point test experiment, which is conducted in three different locations of the school. The test results are as follows: the positioning parameters of GPS signal are: 112.44571 e, 38.01395 n. the signal strength of the strongest direction at the three observation points are - 49dbm, - 58.5dbm and - 65dbm respectively. Through the final received positioning information and the signal strength information received in the later stage, the impact position of the projectile can be found effectively, which proves the feasibility of the search device and improves the effective search means for the recovery of the missile borne recorder.