The invention discloses a measurement method and measurement device for the intensity of a microwave electric field. The measurement method includes the steps of splitting a probe light generated by a first laser into two beams of identical probe light, one of which enters a rubidium cell and the other of which enters vacuum equipment; coupling light, which is generated by a second laser, entering the rubidium cell, coherently exciting hot atoms in the rubidium cell from a ground state to a rydberg state by the coupling light and the probe light, and realizing electromagnetically induced transparency in an atomic vapor chamber; applying a microwave electric field generated by a microwave source onto the hot atoms, and coupling another adjacent rydberg state onto a three-level EIT system to form a four-level system; and respectively probing the two ways of transmission light emitted from the rubidium cell and the vacuum equipment, determining the time difference of the two ways of transmission light by analyzing a dispersion relation between the two ways of transmission light, and thus obtaining the intensity of the microwave electric field.