An electrochemical device, the electrochemical device comprises: a housing, wherein the housing defines an accommodation cavity, the housing comprises a first sidewall, the first sidewall comprises a first wall face oriented toward the accommodation cavity and a second wall face oriented away from the accommodation cavity, and the first sidewall comprises a mounting hole, the mounting hole running through the first wall face and the second wall face; an insulation assembly, connected to the first wall face or the second wall face; the insulation assembly comprises a first insulator, the first insulator comprises a penetrative first through-hole, and the first through-hole communicates with the mounting hole; an electrode post, comprising a first part and a second part, the first part is connected to an end face of the insulation assembly, the end face of the insulation assembly is oriented away from the first sidewall, the first part covers the first through-hole, the second part is disposed in the mounting hole and the first through-hole, one end of the second part is connected to an end face of the first part, and the end face of the first part is oriented toward the first sidewall; and the first insulator is configured to be melted when a temperature in the accommodation cavity rises to a first threshold, and generate, under an action of a gas pressure in the accommodation cavity, a pressure relief channel that communicates the accommodation cavity to an outside of the housing, characterized in that the insulation assembly further comprises a second insulator; in a thickness direction of the first sidewall, the first insulator and the second insulator are stacked together; the second insulator comprises a penetrative second through-hole, the penetrative second through-hole communicates with the first through-hole and the mounting hole, and a melting point of the second insulator is higher than the first threshold. a housing, wherein the housing defines an accommodation cavity, the housing comprises a first sidewall, the first sidewall comprises a first wall face oriented toward the accommodation cavity and a second wall face oriented away from the accommodation cavity, and the first sidewall comprises a mounting hole, the mounting hole running through the first wall face and the second wall face; an insulation assembly, connected to the first wall face or the second wall face; the insulation assembly comprises a first insulator, the first insulator comprises a penetrative first through-hole, and the first through-hole communicates with the mounting hole; an electrode post, comprising a first part and a second part, the first part is connected to an end face of the insulation assembly, the end face of the insulation assembly is oriented away from the first sidewall, the first part covers the first through-hole, the second part is disposed in the mounting hole and the first through-hole, one end of the second part is connected to an end face of the first part, and the end face of the first part is oriented toward the first sidewall; and the first insulator is configured to be melted when a temperature in the accommodation cavity rises to a first threshold, and generate, under an action of a gas pressure in the accommodation cavity, a pressure relief channel that communicates the accommodation cavity to an outside of the housing, characterized in that the insulation assembly further comprises a second insulator; in a thickness direction of the first sidewall, the first insulator and the second insulator are stacked together; the second insulator comprises a penetrative second through-hole, the penetrative second through-hole communicates with the first through-hole and the mounting hole, and a melting point of the second insulator is higher than the first threshold.