Abstract: The information security of the cable trench tube well is connected with the geographic information system(GIS) of the power grid. Most of the monitoring information is uploaded by private protocol to reduce the energy loss in information transmission. However, this kind of private mode is usually easy to crack, and there are hidden dangers of information security. Therefore, an information transmission encryption method for cable trench sensor network based on fusion encryption technology is proposed. By combining homomorphic encryption technology and elliptic curve encryption technology, the encryption and protection of cable operation data transmission are realized, and the decryption private key is protected by combining reversible watermarking technology and image encryption technology. Improved system security and robustness. The experimental results show that the designed information transmission encryption strategy has high security, which proves that the designed information transmission encryption strategy has good encryption effect and has certain application value.