借助“宽带中国”战略和智慧城市试点构造政策协同赋能的准自然实验，基于2010～2021年281个地级市数据，运用双重机器学习算法探究政策协同对数智化发展的激励效应。研究发现：①政策协同显著有利于城市数智化发展，且相较于单一政策表现出更佳的赋能效果；②政策协同还可通过促进非农创业、提高创业活跃度的市场培育机制， 以及诱发政府补贴、强化政府创新注意力的政府扶持机制，“双轮”驱动城市数智化发展；③政策协同的数智化驱动效应在营商环境优良、法制保障完善的城市存在“先发优势”，且中心城市和胡焕庸以东经济区政策协同赋能的积极效果更突出。

This study constructs a quasi-natural experiment of policy synergy with the help of the “Broadband China” strategy and the smart city pilots. It also explores the incentive effect of policy synergy on digital intelligence development based on the data of 281 prefectural cities from 2010 to 2021 by using double machine learning algorithms. The results show that: ①policy synergy significantly contributes to urban digital intelligence development, and shows a better enabling effect than a single policy. ②Policy synergy can also “double wheel” the development of urban digital intelligence through market incubation mechanisms of promoting non-agricultural entrepreneurship and increasing entrepreneurial vitality, and government support mechanisms of inducing government subsidies and intensifying government attention to innovation. ③The digital intelligence driving effect of policy synergy has a “first-mover advantage” in cities with an excellent business environment and a perfect legal system guarantee, and the positive effects of policy synergy are more prominent in central cities and economic zones east of HU Huanyong.