In　this　paper,　we　propose　an　augmented　subspace　method　for　solving　semilinear　parabolic　equations　based　on　the　Symmetric　Interior　Penalty　Discontinuous　Galerkin　(SIPDG)　method.　The　main　idea　of　this　method　is,　at　each　time　step,　to　convert　the　solution　of　the　semilinear　elliptic　problem　into　the　solution　of　the　corresponding　linear　boundary　value　problem　on　the　same-scale　discontinuous　finite　element　space　and　the　solution　of　the　semilinear　elliptic　problem　on　a　newly　defined　low-dimensional　augmented　subspace.　The　prior　error　estimates　are　derived.　Numerical　experiments　are　conducted　to　confirm　the　theoretical　conclusions　and　the　computing　efficiency　of　the　proposed　method.