The invention discloses a KLEIN encryption implementation method based on area and performance balanced optimization. The method includes: optimizing an S box, allowing two modules to share the S box, building a Tab box for fast table look-up, allowing key expansion round constant i to be in a self-adding manner, encapsulating and integrating round key adding, byte substitution, row shifting, line mixing, and key expansion sub-modules into one module, using continuous assignment statement to realize algorithm assignment, updating a clock signal control counter, using Verilog HDL (hardware description language) parallel execution features and the manner integrating the sub-modules into one module, using global synchronization clock pulse triggering, and fully utilizing the device trigger and wiring resources. By the method, the area resource occupation required by implementing the KLEIN encryption algorithm can be saved effectively, encryption speed is increased, and the KLEIN encryption algorithm can be implemented with low hardware area and keep high performance.