Appropriate preload can make the bearing system achieve the purpose of reducing system vibration and noise and improving bearing stiffness. In order to meet the needs of bearing preload control, a preload control strategy based on NRBO algorithm to optimize fuzzy PID is proposed. Firstly, the hydraulic loading method of bearing preload is determined and the transfer function is established. Secondly, combined with the co-simulation model of AMESim/Smilink, and compared with conventional PID, fuzzy PID, PSO optimized fuzzy PID. Finally, the experimental verification is carried out. The simulation results show that the overshoot of fuzzy PID optimized by NRBO algorithm is reduced by 42.93%, 27.78% and 13.91% respectively compared with conventional PID, fuzzy PID and PSO algorithm, and the adjustment time is reduced by 3, 2.3 and 1.6 s respectively. The test results show that under the radial force of light load, medium load and heavy load, compared with the conventional PID controller, the NRBO optimized fuzzy PID controller reduces the adjustment time by 5.3, 10.4 and 4.5 s respectively, and the overshoot is reduced by 43.78%, 52.52% and 72.36% respectively. Compared with the fuzzy PID controller, the adjustment time is reduced by 2.7, 5.2 and 2.6 s respectively, and the overshoot is reduced by 29.62%, 46.24% and 59.52% respectively. Compared with the PSO algorithm to optimize the fuzzy PID controller, the adjustment time is reduced by 1.7, 3.2, 2.3 s, and the overshoot is reduced by 17.38%, 30.02%, and 55.42%, respectively. It shows that the NRBO optimized fuzzy PID controller has faster and more accurate control effect, and can achieve accurate application of preload.