The invention discloses a hydrated 1,2-bis(4-pyridyl) ethylene manganese sulfate ferroelectric functional material and a method for preparing the same. The ferroelectric functional material has the molecular formula of [Mn(bpe)(H2O)2(SO4)].H2O, wherein the bpe is the 1,2-bis (4-pyridyl) ethylene with the molecular formula of C12H10N2. The ferroelectric functional material is yellow powder with the purity of not less than 99% and has the space group structure of C2. The ferroelectric characteristic parameters of the ferroelectric functional material are as follows: the remanent polarization strength 2Pr of 0.5779mu C.cm<-2>, the coercive field 2Ec of 18kv.cm<-1>, and the saturation polarization strength Ps of 0.4117mu C.cm<-2>, wherein the saturation polarization strength of the ferroelectric functional material is 1.67 times that of the Rochelle salt. The ferroelectric functional material is a ferroelectric with excellent ferroelectric properties. The method has the advantages of simple and feasible process, low requirements for equipment, low cost of raw materials, good nucleation and crystal growth, high yield and no pollution.