The invention discloses a manufacturing process of silver-cadmium oxide with an internal oxidation method by matching coarse and fine particles. The manufacturing process comprises the following steps of (1) proportionally putting silver-cadmium oxide components in a medium frequency induction melting furnace for melting and ingot casting; (2) cleaning the surfaces of the cast ingots by turning, then heating and extruding into silver-cadmium alloy wires, drawing, and cutting into segments; (3) putting the segments in an internal oxidation furnace for oxidation in an oxygen atmosphere, performing low-temperature oxidation first, and then performing high-temperature oxidation in an oxidation process; (4) cleaning and polishing the segments which are oxidized and discharged, drying, then pressing into round ingots, and heating and extruding the round ingots into wires in an air furnace; (5) drawing the wires, and performing annealing treatment, so as to obtain finished products of the wires. In the oxidation process, the low-temperature oxidation is combined with the high-temperature oxidation, and the coarse and fine oxide particles are matched and mixed, so that the problem of insufficient material malleability caused by superfineness of the oxide particles is solved, and the comprehensive application level of materials is increased.