The invention discloses a finite element simulation method for a hydraulic tensioner of a top tensioned riser. The method comprises the steps of processing a floating platform into a rigid body, namely, establishing a rigid body connection between the gravity center of the platform and a platform deck (namely, the top of the tensioner), and applying a motion of the platform to the gravity center position of the platform during finite element analysis subsequently, so that the motion of the platform can be correctly transmitted to the top of the riser in combination with the gravity center of the platform, the platform deck (connected with the top end of the tensioner) and a tension ring (located at the top of the riser). According to the method, a tension-stroke relationship characteristic of the tensioner can be reasonably simulated and a relationship among the floating platform, the tensioner and the riser can be correctly handled; and in addition, the tension and motion at the top of a top tensioned riser model better conform to reality, so that the finite element analysis of the top tensioned riser is more reasonable and accurate.