The invention relates to an inverse operation method for a lower triangle complex matrix with any order. The inverse operation method comprises the following steps that (1) a reciprocal obtaining unit is set, and is used for carrying out reciprocal obtaining operation on a diagonal element of an N-order matrix L, and outputting a matrix obtained after reciprocal obtaining operation is accomplished; (2) a multiplication and accumulation unit is set and is used for receiving the matrix obtained after reciprocal obtaining operation is accomplished, and multiplication and accumulation operation is carried out on the first element to the (i-1)th element in the ith row in the matrix; (3) a reciprocal multiplication obtaining unit is set and is used for receiving the accumulation result corresponding to the elements in the ith row of the matrix, reciprocal obtaining operation is carried out on the accumulation result, and then the accumulation result processed through reciprocal obtaining operation is multiplied by a diagonal element in the ith row so that a matrix element of the ith row of an inverse matrix L-1 can be obtained. In the whole process, a plurality of multiplication and accumulation units are used for carrying out parallel calculation. The inverse operation method for the lower triangle complex matrix with any order has the advantages that the inverse operation of the lower triangle complex matrix with any order can be achieved, and restriction caused by the number of operation units does not exist; only the design of a multiply-accumulator with one plural adder and one plural multiplier is adopted, hardware resources are saved, and operation efficiency is ensured through an effective parallelization mode.