Application of exact renormalisation transformation, to Ising model via equiscale transformation in the same universality class, yields a four-branch critical surface and four fixed points. In the case of the ferromagnetic and antiferromagnetic phase transitions, the results are in agreement with the known exact and the best approximate ones very satifatorily. For the supperantiferromagnetic phase transition, we propose the critical surface equation as follows —ch(h) = sh(2Kx)sh(2Ky).