The single mutant BR_E204Q and tri-mutant BR_{I119T/T121S/A126T} of bacteriorhodpsin were constructed by directed-mutation method. The M412 Flash-dynamics spectrum indicates that the life of M intermediate of the single mutant BR_E204Q is 7.10 ms and the life of M intermediate of the tri-mutant BR_{I119T/T121S/A126T} is 8.23 ms, whose lives of M intermediate are longer than that of the wild-type BR with life of the M intermediate 6.23 ms. The result shows that the tri-mutant has the longest M intermediate life which exceeds wild-type BR by thirty-two percent. The Proton-pump functional research of the two mutants illustrates that their proton-pump functions decresae compare with that of wild-type BR respectively and the proton-pump function of the tri-mutant BR_{I119T/T121S/A126T} is the weakest one.