The invention provides a container truck positioning and guidance method based on truck head detection. The method comprises the following steps: 1) mounting an industrial camera on a gantry crane to carry out locating point calibration; 2) detecting a truck head in a video image, and judging moving direction of the truck head according to the truck head position; and 3) judging whether a container exists through line detection, if meeting conditions, calculating deviation angle between an edge of the container and a locating point and relative distance between a right front corner point of the container and the locating point, and transmitting the position of the container in a specified area to a driver through a display device to realize positioning and guidance of a container truck. The method enables the position of the container in the specified area to be transmitted to the driver visually in real time, thereby realizing positioning and guidance of the container truck.