A optimization of PDMS（polydimethylsiloxane）-PDMS bonding technology has been proposed in this paper, PDMS substrate and cover plate has been bonded by adopting different ratio of prepolymers and curing agent.Three methods of contrast experiment has been set in this paper with different cross-linking ratios bonding, oxygen plasma treatment bonding and coating liquid PDMS bonding.Finally,they are applied to microfluidic chip encapsulation testing. The results show that ,after natural bonding,chip has a appropriate strength ,which are reusable, high-efficiency and energy saving. The bonding parameters are as follows: the mass ratio of prepolymers and curing agent used for PDMS substrate and cover sheet is 10:1 and 15:1 respectively. Curing temperature of cover plate is 75 ℃ and the curing time it cost is 40 min.