1. The magnitude and nature of the torque to be transmitted and the requirements for shock absorption and vibration damping. For instance, for high-power heavy-duty transmission, gear couplings can be selected; for severe shock loads or to eliminate torsional vibrations in the shafting, highly elastic couplings such as tire couplings can be chosen.

2. The operating speed of the coupling and the resulting centrifugal force. For high-speed transmission shafts, couplings with high balance accuracy, such as membrane couplings, should be selected, rather than couplings with eccentricities like slider couplings. Couplings are used in conjunction with various host products, and the surrounding working environment is complex, such as temperature and humidity conditions, which are important factors to consider when choosing couplings.

3. The magnitude and direction of the relative displacement between the two shafts. When it is difficult to maintain strict alignment between the two shafts after installation and adjustment, or when there will be significant additional relative displacement during operation, flexible couplings should be selected. For example, when the radial displacement is large, slider couplings can be chosen; for large angular displacements or connections of intersecting shafts, universal couplings can be selected.

4. The reliability of the coupling and the working environment. Generally, couplings made of metal components that do not require lubrication are more reliable; couplings that require lubrication are more susceptible to the influence of the completeness of lubrication and may pollute the environment. Couplings containing rubber and other non-metallic components are sensitive to temperature, corrosive media, and strong light, and are prone to aging.

5. The manufacturing, installation, maintenance, and cost of the coupling. Under the premise of meeting the performance requirements, couplings that are easy to install and disassemble, simple to maintain, and low in cost should be selected. For example, rigid couplings not only have a simple structure but also are easy to install and disassemble, and can be used in low-speed, high-rigidity transmission shafts. General non-metallic elastic element couplings, due to their good comprehensive performance, are widely used in general medium and small power transmissions.