The invention relates to a MFI structure molecular sieve containing phosphorus and transition metals, and a preparation method thereof. According to the MFI structure molecular sieve of the present invention, phosphorus distribution D meets the following conditions that D is more than or equal to 0 and less than or equal to 0.8, and is equal to P(S)/P(C), wherein P(S) represents the phosphorus content in a part from the edge to 1/5 of the center of the molecular sieve grain characterized by using a TEM-EDX method, P(C) represents the phosphorus content in the center of the molecular sieve grain, and no absorption peak exists at 1633 cm<-1> on an infrared spectrogram obtained by adopting 3-methylpyridine as a probe. The preparation method for the molecular sieve comprises: mixing the calcined MFI structure molecular sieve containing phosphorus and transition metals with a silicon source, carrying out reaction crystallization for 2-80 hours at a temperature of 145-190 DEG C, carrying out separating and drying, and carrying out calcination at a temperature of 400-800 DEG C. The molecular sieve of the present invention is used for catalytic cracking, wherein light olefin yield is high, and yields of coke, hydrogen and dry gas are reduced.