S1, in any time slot, receiving, by a base station, pilot frequency sequence signals with a certain length sent by all active users in an environment to obtain receiving signals, wherein the receiving signals are signals after the pilot frequency sequence signals are influenced by environment;

S2, converting an environmental sensing problem of a specific target into a compressed sensing reconstruction problem using the receiving signals in the step S1 based on a multi-beam multi-carrier millimeter wave channel model;

S3, solving the compressed sensing reconstruction problem in the step S2 based on an approximate message passing method to obtain a coarse environmental sensing initial result;

S4, selecting a predetermined region as a region of interest from whole environment based on the coarse environmental sensing initial result, and dividing and determining a target object in the region of interest according to a background determining method and removing influence of background scatters outside the region of interest on the receiving signals to obtain receiving signals corresponding to the target object;

S5, calculating an environmental sensing result based on the receiving signals corresponding to the target object obtained in the step S4; and

S6, repeating the steps S4 and S5 in sequence until an algorithm convergence, to obtain a final environment sensing result.