Research conclusions:By calculating the positional accuracy required forCPócontrolnetwork based on the parameter adjustmentof side-angle measurement network, the result shows the improved CPIII net form is better in integration intensity, but it isworse in positional accuracy, especially in lateral accuracy, compared with the CPónetwork. For the CPónetwork, the repeatablemeasurement accuracy should be less than?1. 5 mm and the coordinate difference tolerance should be less than?3. 0 mm in the direction coordinate ofxandy. For the improved CPónet form, the corresponding repeatablemeasurement accuracy and permissible difference should be less than?2.0 mm and?4.0 mm respectively.