Abstract: With the continuous improvement of the demand for titanium alloy parts with thin-walled structure in the engineering fields such as aviation, aerospace and shipping, the machining efficiency is relatively higher and the micro-milling method suitable for the manufacturing of complex geometric shapes such as curved surface has been widely used in the titanium alloy thin-wall machining. However, due to its low stiffness, the deformation, instability and vibration of workpiece can easily occur when the titanium alloy thin-walled parts are machined by micro-milling, and the machining accuracy is reduced. In this paper, the status of research on thin-walled micro-milling with weak stiffness at home and abroad is analyzed from three aspects: theoretical modeling, finite element simulation and experimental measurement. It is shown that accurate prediction of thin-walled deformation in machining process is of great significance to the establishment of error compensation model and improvement of machining accuracy. It is pointed out that the physical relationship between the deformation of thin-walled micro-milling and the effect of the deformation on the machining accuracy is still to be further studied.