We consider an infinite ferroelectric superlattice in which the elementary unit cell is made up of l atomic layers of type A and p atomic layers of type B. Based on the transverse Ising model we examine the phase transition properties of the ferroelectric superlattice. Using effective field theory with the transfer matrix method, we derive a nonlinear equation for the phase transition temperature of the superlattice with an arbitrary layer-number in one period and arbitrary exchange constants. Numerical results are given for the dependence of the Curie temperature on the layer-number and the interface exchange constant of the superlattice.