Radiotherapy plan optimization system and device and storage medium

The embodiment of the invention discloses a radiotherapy plan optimization system and device and a storage medium. The system comprises one or more processors and a storage device, wherein the storagedevice is used for storing instructions, and the processors are used for executing the instructions to achieve the following steps: a, acquiring an ideal dose volume histogram of a region of interest; b, performing first optimization based on the ideal dose volume histogram and the weight of the current region of interest, and determining a current dose volume histogram; c, performing second optimization based on the ideal dose volume histogram and the current dose volume histogram of the region of interest, determining the weight of the updated region of interest, returning the updated weight of the region of interest to the step b, and sequentially executing the first optimization and the second optimization until a termination condition is met. According to the invention, the weight ofthe current region of int