The invention discloses an ultrathin microcellular foaming rubber yoga sports mat. The ultrathin microcellular foaming rubber yoga sports mat comprises a microcellular foaming rubber layer and fiber woven mesh fabric compounded at the bottom of the microcellular foaming rubber layer. The microcellular foaming rubber layer is prepared from, by weight, 20-60 parts of unvulcanized rubber, 10-50 parts of filler, 1-20 parts of oil, 1-5 parts of vulcanizing agent, 0.5-5 parts of accelerant, 0.5-3 parts of antiager, 2-6 parts of foaming agent and 1-5 parts of dispersant. The invention further discloses a preparation method of the yoga sports mat. The yoga sports mat is prepared from microcellular foaming rubber, only one layer of structure is arranged, the thickness of the mat can be controlled to be very small, the mat is convenient to carry by customers, the fiber woven mesh fabric is compounded at the bottom of the microcellular foaming rubber layer, and the product avoids the situation that the shape is changed due to external force.