The Ashele basin is an important ore concentration area in the southwestern margin of Altay. The famous Ashele Cu- Zn deposit of volcanic massive sulfide type (VMS) occurs in China. The geochemical characteristics of both volcanic and intrusive rocks in the Ashele basin record the tectonic magmatic evolution, diagenesis and mineralization processes in this basin. However, the tectonic background and mineralization mechanism of the Ashele basin has always been controversial. This paper reports the zircon U- Pb age (376.7±1.3 Ma) of tonalite in the core of the Saershuoke Cu polymetallic deposit in the Ashele ore concentration area. Based on the geochemical characteristics, isotopic geochronology and regional magmatic rocks including volcanic, subvolcanic and intrusive rocks in the Ashele area, the authors believe that the Devonian volcanic rocks and Habahe intrusive rocks in the Ashele area may have had different stages and ages in the same geological tectonic setting. The bimodal volcanic rocks, which are closely related to mineralization in time and space, are the products of eruption, overflow and intrusion of different deep magma sources with different properties under the background of rapid extension. Mantle plume upwelling resulted in plate fragmentation, rapid extension along the basement fault system and continuous supply of mantle- derived magma may be the main deep dynamic mechanism for the formation of bimodal igneous rocks and the Ashele high Mg volcanic rocks.