The present invention provides a method for locating the node of the spatial structural sphere, the method is equivalently transferring the sphere center of the special sphere which can not be measured, and converting the three-dimensional special coordinate of the sphere center to two-dimensional plane coordinate and out-of-plane relative scale height, in actualizing all sphere centers are wholly projected and converted to the horizontal reference plane, in installing the plane position of the sphere center is arranged at the upper side of the plane, and a sphere center is arranged at the position which is at vertically upside or downside of the plane position, namely the sphere center of the node of the actual spatial structural sphere. The locator is composed of a base frame formed by vertically welding the sleeve on the baseboard, a top holder formed by vertically welding the screw bolt on the roof plate, a nut matched with the screw bolt and a bolt, the nut is movingly located at the upper end of the sleeve, the lower segment of the screw bolt is inserted into the sleeve, the roof plate is arranged with screw holes which comprises equilateral triangle and are matched with the bolt, and the gravity center of the triangle is overlapped with the center of the roof plate. The invention changes the sphere center to the measurable point, and to the plane point and out-of-plane relative scale height, the measuring is more convenient and the precision is higher, the arranging eccentricity is small and the operating efficiency is high.