A robotic arm control system is provided. In, the robotic arm control system, any three points A, B, and C of an object to be determined are picked, thereby creating an original coordinate system. A robotic arm is directed to rotate around the x-axis of the original coordinate system to reach the points B and C. During the rotation of the robotic arm, the three points A, B, and C are recorded by a visual process. A non-linear mapping relation of the original coordinate system and the operation coordinate system is calculated according to length ratios, an angular ratio, and a differential ratio of the difference of the length ratios to the angle between the line A-B and the line A-C, thereby controlling the movement of the robotic arm according to the non-linear mapping relation. The disclosure further provides a robotic arm control method.