Abstract: Based on the principles of biological neuroendocrine gland hormone regulation and the fractional order calculus, and considering that the pressurizer system of nuclear power plant is a very complicated system, a endocrine fractional order PI^λD^μ controller was designed with long feedback and ultra-short feedback, in order to obtain satisfactory control results. The primary controller is proportional control. According to the system errors, it can adjust the control parameters of the secondary one dynamically and eliminate the control error quickly and stably. The secondary is fractional order PI^λD^μ controller and a indirect algorithm (Oustaloup algorithm) was used to implement the fractional order controller. The system can be more excellent in velocity, precision and anti-interference ability. Simulation results show that the endocrine fractional order PI^λD^μ controller is with better performance and strong anti-interference ability than the traditional PID control.