A method for processing a video image, comprising: receiving an original video image; adjusting a signal clock frequency of the original video image to acquire a processed video image; after a command signal input by a user is received, capturing the processed video image according to a preset size to acquire a video image corresponding to a display window of the preset size; and encoding the video image corresponding to the display window of the preset size to acquire an encoded video image, characterized in that the command signal comprises a preset abscissa and a preset ordinate, wherein after the command signal input by the user is received, the step of capturing the processed video image according to the preset size to acquire the video image corresponding to the display window of the preset size comprises: performing a pixel point computation according to a first formula to acquire the maximum number Ho of horizontal pixel points of the display window of the preset size, wherein the first formula is: Ho = Po Pi × Hit − Hos, wherein the Po is a fixed pixel clock frequency, the Pi is a pixel clock frequency of the original video image, the Hit is the total number of line cycle clocks of the original video image, and the Hos is a spacing of effective pixels between two lines of an output video; capturing the horizontal pixel points with the maximum number of the display window of the preset size according to the preset abscissa to acquire horizontal pixel points of the display window of the preset size; adopting vertical longitudinal points of a resolution of the original video image as vertical longitudinal pixel points of the display window of the preset size; and capturing the processed video image according to the horizontal pixel points and the vertical longitudinal pixel point of the display window of the preset size to acquire the video image corresponding to the display window of the preset size. receiving an original video image; adjusting a signal clock frequency of the original video image to acquire a processed video image; after a command signal input by a user is received, capturing the processed video image according to a preset size to acquire a video image corresponding to a display window of the preset size; and encoding the video image corresponding to the display window of the preset size to acquire an encoded video image, characterized in that the command signal comprises a preset abscissa and a preset ordinate, wherein after the command signal input by the user is received, the step of capturing the processed video image according to the preset size to acquire the video image corresponding to the display window of the preset size comprises: performing a pixel point computation according to a first formula to acquire the maximum number Ho of horizontal pixel points of the display window of the preset size, wherein the first formula is: Ho = Po Pi × Hit − Hos, wherein the Po is a fixed pixel clock frequency, the Pi is a pixel clock frequency of the original video image, the Hit is the total number of line cycle clocks of the original video image, and the Hos is a spacing of effective pixels between two lines of an output video; capturing the horizontal pixel points with the maximum number of the display window of the preset size according to the preset abscissa to acquire horizontal pixel points of the display window of the preset size; adopting vertical longitudinal points of a resolution of the original video image as vertical longitudinal pixel points of the display window of the preset size; and capturing the processed video image according to the horizontal pixel points and the vertical longitudinal pixel point of the display window of the preset size to acquire the video image corresponding to the display window of the preset size. performing a pixel point computation according to a first formula to acquire the maximum number Ho of horizontal pixel points of the display window of the preset size, wherein the first formula is: Ho = Po Pi × Hit − Hos, wherein the Po is a fixed pixel clock frequency, the Pi is a pixel clock frequency of the original video image, the Hit is the total number of line cycle clocks of the original video image, and the Hos is a spacing of effective pixels between two lines of an output video; capturing the horizontal pixel points with the maximum number of the display window of the preset size according to the preset abscissa to acquire horizontal pixel points of the display window of the preset size; adopting vertical longitudinal points of a resolution of the original video image as vertical longitudinal pixel points of the display window of the preset size; and capturing the processed video image according to the horizontal pixel points and the vertical longitudinal pixel point of the display window of the preset size to acquire the video image corresponding to the display window of the preset size.