To solve the problem of maneuvering target detecting and tracking in a low SNR environmenta Track Before Detect (TBD) algorithm combining the auxiliary particle filtering with multiplemodel particle filtering (APFMMPF) was studied.Predict particles in the multiplemodel particle filtering processwhich contained target existence and moving mode variableswere directly used to produce auxiliary variable for conducting auxiliary particle filtering and realizing the detection and tracking of maneuvering target.It could be seen from the simulation result of APFMMPF algorithm and pure MMPF algorithm that: with higher detection probability and smaller tracking errorthe detecting and tracking performance of APFMMPF algorithm was superior to that of MMPF algorithm.Due to the usage of current measurements in the process of sampling particlesthe APFMMPF algorithm can improve the performance of detecting and tracking the maneuvering target.