The Qaidam basin is the largest Mesozoic and Cenozoic intermountain basin in the north of qinghai-tibet plateau. Surrounded by aljinshan mountain, qilian mountain and kunlun mountain, it forms a tectonic pattern of "three mountains and one basin" and has a complex relationship between basin and mountain. Based on the fine structural interpretation of seismic data in the western part of the qaidam basin, it is first discovered that the lower part of the yuejin no.2 east structure is positive flower-like structure, while the upper part is negative flower-like structure. Tectonic evolution profile analysis show that strike-slip tectonic development has experienced seven springs group of the late sedimentary strong compressive shear structure, the development is flower tectonic style, to the prophase of qaidam group sedimentary structure by experienced strong transtensional tectonic setting, develop a negative flower structure, and superimposed over early positive flower structure, and makes the shallow layers of main development normal fault, two phase of the superposition of strike-slip faulting produced today"s complex negative inversion of strike-slip fault zone. The northern part of the qaidam basin also has the same structural characteristics, so it can be inferred that the qaidam basin is an oblique compression-torsional structure affected by the aljin strike-slip fault and a pull-apart basin within the main displacement zone of the non-strike-slip fault. It is of great significance to study the tectonic development and evolution in the qaidam basin.