The invention discloses a gene sequencing data simulation system and method for simulating crowd background information. A target capture area file, sequencing depth, seven types of mutation, frequencies of mutation occurrence, and coordinates of mutation on a reference genome are input, the number of templates is determined based on the sequencing depth, the probability distribution of the corresponding template length is generated by using an acceptance rejection algorithm, each template is traversed, the number of the templates which have been traversed is determined, when not all the templates are traversed by the algorithm, copy number mutation simulation, single nucleotide site mutation simulation, gene fusion simulation, tandem repeat simulation, inversion mutation simulation, insertion fragment simulation and deletion fragment simulation are performed on each of the extracted length templates, and reads are generated and written into a sequencing file; when all the templates are traversed, the generation of the sequencing file is completed; read comparison is performed, the simulated sequencing file and a comparison file thereof are output, and the simulation is completed.The gene sequencing data simulation system and method for simulating crowd background information can be used for easily and quickly obtaining a sample containing specific mutation.