The concept of fractional order skyhook damping control was presented based on fractional calculus theory. Taking a suspension model controlled by the new skyhook damping as the reference model,a new excellent sliding mode control strategy for suspension systems was proposed and applied in the control of a nonlinear suspension. A kind of numerical scheme for fractional order system with high accuracy and stability was also given. The new sliding mode control for an active suspension with nonlinearities was investigated through numerical simulation. The computational results verify the good control efficacy of the new strategy.