The present invention relates to a surgical robot system and a method for displaying position of a surgical instrument. The surgical robot system comprises an image arm, a tool arm, a display unit, and a computing unit. The image arm can connect to an endoscope configured to collect image information. The tool arm is a remote-center-of-motion point mechanism and configured to connect to a surgical instrument. The surgical instrument comprises at least one feature point identifying position information of the surgical instrument. The display unit is communicatively connected to the computing unit. The tail end of the endoscope is provided with an endoscope coordinate system. The computing unit is configured to obtain a coordinate value of the feature point in the endoscope coordinate system according to a kinematics equation, obtain the position information of the surgical instrument in an endoscope lens plane according to the coordinate value, and perform graphical processing on the position information. The display unit receives and displays the graphically processed position information, thereby improving surgical safety and efficiency.