The time independent and time dependent canonical transformations based on the multiplication of symplectic matrix were given for Hamilton system. The approximate Hamilton system with parametric variable was introduced, and the canonical transformation was performed based on this approximate Hamilton system. The symplectic preserving property of the numerical methods was guaranteed by the canonical transformation, and the energy in the integration time can be adjusted to be constant by changing the parametric variable. So the symplectic and energy preserving method for Hamilton system was obtained.