pH detection is related to human beings' life closely. Herein, a porous metal hydrogen-bonded organic framework (MHOF) Co-CDI-CO32- was designed and synthesized, which could be utilized to detect the pH values of strong acids. The sensitivity of pH detection was in the range of pH 2.0-2.4 with an accuracy of 0.1, which mainly depended on the different degree of crystal surface damage. The MHOF Co-CDI-CO32- had potential applications with the advantages of low cost, easy storage, and great sensitivity for pH detection as a pH sensor.