For the problem of voltage tracking on the trapezoidal brushless DC motor (BLDCM) with stochastic disturbance,a simple adaptive nonlinear controller with a saturation term,which can overcome the phenomena of voltage saturation and stochastic disturbance arising from voltage tracking and make the controlled system track the reference,was designed by introducing a saturation function and an adaptive parameter.Theoretically,the system is globally uniformly ultimate bounded.Numerical experiments show that the controlled system achieves disturbance attenuation with satisfactory voltage tracking.