1. A method for determining ricochet vectors of a probe of a coordinate measuring machine (CMM) being executed by a processor of a computing device, the method comprising: setting an approach distance between the probe and a manufactured object, and storing the approach distance into a storage system of the computing device; obtaining coordinates of a center of the probe and an initial vector of the probe for each measurement point of the manufactured object when the probe is manually operated to measure the manufactured object; fitting a measurement element of the manufactured object according to all measurement points of the manufactured object; and for each measurement point, calculating an approach point of the manufactured object according to the approach distance and the initial vector of the probe, determining a position relation between the approach point and the measurement element of the manufactured object, calculating a ricochet vector of the probe according to the position relation, and storing the ricochet vector of the probe into the storage system.