The invention relates to a self-repairing elastic soft material based on a natural rubber and a synthesis method thereof, and relates to the rubber soft material and the synthesis method thereof. Thesynthesis method comprises the steps of firstly, carrying out epoxidation on a partial double-bond in a natural rubber molecule main chain: adding formic acid and hydrogen peroxide into a natural latex or a prepared natural rubber latex so as to carry out epoxidation on the double-bond; then using a pH value modifier for modifying a pH value of a latex system; finally, adding a multifunctional-group modifier and an accelerant, and preparing to obtain the self-repairing elastic soft material. The material has a rapid and high-efficient self-repairing performance under a mild temperature condition, and is good in flexibility and big in deformation. Without any applied force stimulating, two cut surfaces are naturally spliced for 2h at the room temperature and the temperature of 50 DEG C, andthe self-repairing efficiency respectively reaches to 50.6 percent and 81.5 percent. The shearing modulus range is 0.5 to 2.0MPa, and the elongation at break is 400 to 1200 percent. The self-repairing elastic soft material has an important application value in the fields of electronic skins, artificial muscles, adhesives, coatings and the like.