Novel subsurface constructed wetland

The invention discloses a novel subsurface constructed wetland which comprises a pool body, a matrix layer as well as a water inlet pipeline and a water outlet pipeline, wherein the matrix layer respectively comprises a base layer, a generation layer, a barrier layer and a growth layer from bottom to top; the particle size needs to meet the conditions as follows: the sizes of the base layer, the generation layer, the barrier layer and the growth layer are gradually decreased; and the matrix layer takes the generation layer as a principal layer. According to the arrangement of water inlet horizontal pipes of different heights, blockage risk of the water inlet is reduced; the sheltering layer is capable of effectively avoiding direct sunlight, heat generated by absorption of light is reduced, and the influence on microbial nitrogen removal performance is small; the pool body can be protected by a fixing rack, so that the pool body has firmness; due to arrangement of matrixes of differentparticle sizes, microbia