At present, API standard conductivity room is usually used for proppant fracture conductivity test, while the API standard conductivity room is not designed with difficulty in production and processing of rock plates, which results in inconsistency (fracture) between rock plate and the design of conductivity room and further affect factuality and reliability of experimental data. In order to gain a better understanding for the effect of rock-plate sealing on the conductivity of the API standard conductivity room and the experimental data, a variety of sealing test methods are performed, and the DL-2000 acid-etching fracture conductivity test device is used to test the data before and after the change. The results show that API standard conductivity room rock board sealing cannot be ignored and there are simple and complex methods for rock sealing. Complete sealing is almost impossible. In the absence of any sealing measures in the case of  conductivity test, deviation rate is nearly 20%. The use of rubber plus silicone rubber for sealing is recommended for easy manufacturing, lower cost, repeated use and good sealing performance.