The invention discloses a method and a device for matched filtering in combined detection. When a matched filtering device calculates matched filtering data of each symbol of each virtual spread spectrum unit, a complex operation between matched filtering matrix data and antenna data is decomposed into four real operations on four groups of operation subunits in parallel, and the operation subunit number in each group of operation subunits is the same as the antenna number; and when the matched filtering data of one symbol are calculated, each operation subunit in the group firstly finishes areal product accumulation operation decomposed into the group from multiple complex product accumulation operations corresponding to the antenna, then accumulates the operation result of each operation subunit in the group, and finally adds two of four accumulated sums and subtracts the other two to obtain a real part and a virtual part of the matched filtering data of the symbol. The device adopts a universal circuit apparatus with a simple structure and low cost, and a hardware realizing method is provided for the matched filtering operation.