Poly(butyl methacrylate) was synthesized via suspension polymerization. Poly(butyl methacrylate) solution was prepared by dissolving it in N, N-dimethylformamide. With benzoyl peroxide as an initiator, hydroxyethyl methacrylate as a physical crosslinker and divinylbenzene as a chemical crosslinker, the spinning solution containing a semi-interpenetrating polymer network structure was produced by initiating the polymerization of physical and chemical crosslinkers in the poly(butyl methacrylate) solution. Then, the spinning solution was electrospun into fibrous mat. Finally, contact angle of the surface of the fibrous mat for water or light petroleum was analyzed by a contact angle tester. Thermal property, crystallization behavior, and morphology of the fibrous mat were also characterized through thermogravimetric analyzer, X-ray diffractometer, and field emission scanning electron microscopy. In addition, its oil-absorptive property and capacity to separate oil from water were investigated.