For SU(2) lattice gauge theory, three alternative forms of action proposed by us are studied by means of Monte Carlo method, their internal energy per plaquette and specific heat are calculated. The curves of their internal energy approach to the same weak-coupling approximation when β is large. There are peaks on their specific heat curves which indicate the critical points of transition from strong-coupling to weak-coupling. We find clear evidence showing that the deviation of critical point is only due to the difference of higher order terms of lattice spacing a.