With the rapid depletion of conventional natural gas resources in China and the increasing demand for natural gas as well as the improvement in the exploitation technologies of natural gas, the development of unconventional natural gas resources is rather urgent and feasible day by day and possible at the same time. However, the development of unconventional natural gas fields in China started rather late and slowly, lacking experience. In order to alleviate the conflict between the demand and supply, the development of unconventional natural gas is developing rather rapidly now. In this paper, the unconventional natural gas fields in Sichuan Basin were set as the research objects, with the comparison between two development models --- independent development and joint development, and a comprehensive benefit evaluation system was built with such indexes as technologies, costs, management and risks. Through the study, it showed that the benefit from independent development model outweighed that from the joint development, and the reason for it lay in that the cost indexes in independent development model were far lower than that in joint development model, which covered a rather big portion in the evaluation system. But, if the operators in joint development projects could strengthen the cost control, and cut it down equivalent to the cost level in independent development model, the benefits from joint development model would be better than those in independent development model. Such conclusion would provide references for decision making in the development and exploitation of unconventional natural gas fields.