Abstract: A high anti-interference microsystem based on System In Package (SIP) for a power grid is provided. The high anti-interference microsystem comprises a ceramic cavity, a ceramic substrate, a magnetic cover plate, a digital signal processing circuit, an analog signal conditioning circuit and a shield, wherein the ceramic cavity supports the ceramic substrate, the magnetic cover plate is in sealed contact with the ceramic cavity, and the ceramic substrate is arranged in a cavity formed by the ceramic cavity and the magnetic cover plate; a sealed shell of the microsystem based on SIP is composed of the magnetic cover plate and the ceramic cavity; the digital signal processing circuit and the analog signal conditioning circuit are arranged on the ceramic substrate and respectively process received signals to be processed; the shield covers an outer side of the sealed shell and is used for shielding external magnetic field interference.