The creation of a national all-for-one tourism demonstration zone aims to promote the transformation of the tourism industry from a "scenic area tourism" to a "all-for-one tourism" development model, and to promote the development of regional tourism economy through the transformation and upgrading of tourism and the improvement of quality and efficiency. However, whether the creation of the national all-for-one tourism demonstration area has actually promoted the development of regional tourism economy remains to be further verified. In this paper, with the help of the "quasi-natural experiment" of the creation of the national all-for-one tourism demonstration area, based on the 282 prefecture-level cities in 2013-2017 Panel data, this paper uses the difference in difference method to empirically test the impact of the creation of a national all-for-one tourism demonstration zone on regional tourism economic development and its mechanism, and further explores the regional differences. The study found that the creation of a national all-for-one tourism demonstration zone effectively promoted the development of the regional tourism economy. After a series of robustness tests, the conclusion is still significant, and it mainly affects through infrastructure, public services, opening up, and industrial structure. In addition, compared with the developed areas in the east, the tourism economic effect of creating a national all-for-one tourism demonstration zone in the less developed areas in the central and western regions is more obvious. Based on this, it is proposed to create a national all-for-one tourism tourism demonstration zone according to local conditions, guide the development of regional tourism economy in a classified manner, focus on improving the level of tourism infrastructure, public services, and openness to the outside world in the demonstration zone, optimize the industrial structure, and actively promote cross-regional tourism cooperation in the east, middle, and west.