The invention relates to a titration end point determination device for determining a fatty acid value of grain, which comprises a shell, a burette, a titration cup, a magnet stirrer, a stir bar, a light source and a light sensing element, and is characterized by also comprising a constant flow source circuit and a singlechip, wherein, the light source is connected with the constant flow source circuit; the light sensing element is connected with the singlechip; the shell is in a cuboid shape with a cylindrical through hole; the titration cup is transparent cylindrical glass, and is placed inthe shell; the light source is a high-power white light-emitted diode (LED); the light sensing element is a color sensor; and the LED and the color sensor are arranged on the inner wall of the shell at a 90-degree interval. Compared with the prior art, the device provided by the invention has the advantages of adopting the high-power white LED as the light source, needing no measurement darkroom,adopting the color sensor to detect the solution color, and automatically determining the titration end point by the singlechip, having simple structure and low cost, being matched with manual titration for use, and being beneficial for promotion and popularization.