With the development of information security and communication technology, random number has been widely used in security chip, secure communication and other fields. In order to make the implementation of random number online detection method more quickly, this design optimized and derived the Chi-square test formula, which was convenient for hardware implementation. For each random number detection length of 128 bit, 256 bit and 512 bit, the more complex part of Chi-square test formula was removed by derivation, and the formula which was convenient for hardware implementation was obtained, so the formula was easy to be optimized and implemented by hardware. The correctness of the design was verified by VCS and Verdi simulation. Finally, the design was synthesized by using UMC55 technology library with Design Compiler tool. The area of 128 bit Chi-square module was 1 411 GE (number of equivalent NAND gates), which achieved a significant optimization effect while occupied a smaller area. Compared with the software implementation, the speed of 512 bit Chi-square module was increased by 50.08%, achieving higher random number online detection speed. It could be applied to hardware implementation scenarios with small area and high speed.