Based on the impression that the integrated regional development of the Yangtze River Delta has been levelled up as China’s national strategy, it is a necessity to realize the high-quality interconnected development of the Yangtze River Delta National Innovation Demonstration Zone. Specifically, it involves the building of evaluation indexes for the interconnected development level of the demonstration zone from such dimensions as industry, economy, policy, space and ecology, determination of weights of various indexes based on the aggregation method for the expert judgment matrix, and design of an evaluation model for the interconnected development level. On this basis, the interconnected development level between different demonstration zones and the contributions of different indexes to the interconnected development level are studied by conducting empirical study on the evaluation of the interconnected development level of demonstration zones.