The invention provides a memory reusing method and a memory reusing device for a dynamic link library. The method comprises the steps of acquiring parameter data, a variable and a function in the dynamic link library via an acquisition function in a process; judging whether the parameter data, the variable and the function are data structures up to standard; if yes, judging whether the parameter data, the variable and the function can be reused; performing passthrough of the parameter data, the variable and the function to another auxiliary process, allowing the auxiliary process to divide the parameter data, the variable and the function into a global type or a local type and making a statement, and calling the main function to perform effective reuse. According to the memory reusing method for the dynamic link library, the most parameter data, variables and functions can be effectively reused.