The invention discloses a sales locking method and system based on caching, and the method comprises the following steps: S1, dividing commodity information into a plurality of parts according to themodulus of a commodity code, and respectively storing the commodity information in a cache library of a corresponding code of Redis according to a preset rule; S2, obtaining and analyzing a sales locking request of the commodity to obtain a request list; S3, recording an inventory change intermediate table in the same transaction according to the request list, and then updating the commodity information in the cache library of the corresponding code of the Redis; and S4, asynchronously updating the commodity information in the database by using the second-level JOB according to the inventory change intermediate table. According to the method, the use of a single Redis cache library for storing a large amount of data is avoided; query efficiency is improved, atomicity of LUA scripts is usedfor replacing database affairs to guarantee data consistency, inventory concurrency control is conducted by means of the characteristics of Redis single threads, and the gray scale state is used forsolving the problem that cache and database data are inconsistent due to data processing when requests come in the process of switching the data to the cache.