Inspired by the experimental synthesis of the first theoretically predicted clathrate hydride CaH6 with high Tc of 215 K at 172 GPa, we designed a series of Pm-3m phase ternary hydrides MXH12 and performed high-throughput calculations. Ten compounds were discovered, among which YHfH12, YThH12, ScZrH12, and LaThH12 show good superconductivity with critical temperatures above 150 K. LaThH12 and YCeH12 can be dynamically stable at a minimum of 100 GPa. Aiming at a comprehensive description of the H24 cage that dominates the superconductivities of MXH12, we proposed a variable AE, which is defined as the average ELF value at the center of all the H–H bonds in the cage-like hydrides. Combining the AE with the contribution of the H element to the total DOS at the Fermi level, we constructed a simple liner model (called the AE model) by fitting the data of hydrides MXH12. The mean absolute error is 11.7 K suggesting a strong linear correlation between AE and Tc. Furthermore, the AE model can be generalized to predict the superconductivity of other cage-like hydrides such as LaH10 (or YH10) with H32 cage, YH9 (or CeH9) with H29 cage, and more complex cage-like hydrides such as La4H23 and LaBeH8. The AE model could estimate the Tc of clathrate hydrides with small computational cost and provide reliable reference for further high-throughput calculations and experimental research.