The invention relates to polyester-type bioengineering rubber and a preparation method thereof. The method comprises the steps of using aliphatic diol, aliphatic saturated dicarboxylic acid and unsaturated dicarboxylic acid derived from renewable resources as raw materials, synthesizing unsaturated aliphatic polyester with the number average molecular weight between 19,800 and 55,000 and the weight average molecular weight between 88,610 and 222,500 by a direct polycondensation method and performing chemical crosslinking through oxides, wherein reinforcing agents (such as white carbon black, carbon black and the like) can be added in a crosslinking process. Obtained rubber can be molded by adopting the prior rubber processing technology. The raw materials of the rubber do not depend on fossil resources, and the method is simple in preparation process and can replace partial non-renewable resources with the renewable resources so as to obtain the rubber material with equivalent performance.