We present the reheating constraints on an inflationary universe induced by perfect fluid models. Starting with the descriptions for the observables of the scalar field inflationary models in the reconstructed methods, we outline the procedure of perfect fluid inflationary models through these methods to calculate the inflationary observables and reheating. We show that the reheating e-folds number Nre and the reheating final temperature Tre are bound depending on the finite range of reasonable values of wre. By restricting the equation-of-state parameter in the reheating stage, - < wre < 1/3, more stringent constraints can be derived for the model’s parameter space of perfect fluid. These constraints correspond to viable values of the scalar spectral index ns and tensor-to-scalar ratio r, released by Planck2018 observational data.
