The invention provides an accurate seed sowing device with variable depths of mould holes, which comprises a shell body with upper and lower openings, an outer grooved wheel arranged inside the shell body, a brush wheel and a mould hole wheel, wherein the axial lines of the outer grooved wheel, the brush wheel and the mould hole wheel are in parallel. The outer grooved wheel, the brush wheel and the mould hole wheel are installed on three shafts of a seeder through linkages respectively. The rotation directions of the brush wheel and the mould hole wheel are opposite to that of the outer grooved wheel. The accurate seed sowing device is characterized in that the holes of the mould hole wheel are through holes. A loose pin sheathed with a spring is fit in each hole with clearance. A mould hole is formed by the hole of the mould hole wheel and the outer end of the loose pin. The outer grooved wheel is positioned above the mould hole wheel and the outlines of the outer grooved wheel and the mound hole have a distance of 20mm to 40mm. One side of the outer grooved wheel is closely jointed with the inner wall of the shell body while the other side thereof and the inner wall of the shellbody form a seed channel. One side of the mould hole wheel, which is close to the seed channel, is closely jointed with the inner wall of the shell body. The brush wheel is positioned away from the seed channel and obliquely on the mould hole wheel, and is in contact with the mould hole wheel. An additional cam and the mould hole wheel are fixed on the shell body coaxially and the additional camis positioned at the center of the mould hole wheel. The outline of the cam is in contact with the inner end of the loose pin. The seed sowing device has high single grain rate and little damage to seeds.