A text image trimming method, according to the following steps: step 1, obtaining text image data; step 2, using straight line detection method to detect the straight lines of the text image, obtaining edges of a trimmed quadrangle; step 3, detecting text on the image data, obtaining the coordinates of the boundary points of a text region; and step 4, obtaining the final trimming result according to the results of steps 2 and 3. The method can automatically detect the edges of the text region and utilize the detected text region to verify and remove unrelated redundant information thereby, allowing the user to only see the portion containing the text region useful to the user when viewing image data.