The invention relates to a spiral impeller of a super-cavitation centrifugal pump. The impeller is mainly composed of a blade, a front impeller cover plate and a rear impeller cover plate. The technical scheme is as follows: a single spiral blade is adopted and the geometrical shape of the inlet of the blade is transformed to achieve the requirements of a super-cavitation blade; a groove is formed in the back surface of the single spiral blade and close to a suction port; an initial cavity is formed at the groove during running of the super-cavitation pump; and the initial cavity is capable forming a stable super cavity along the back surface of the blade, and the whole smooth and stable super cavity covers the back surface of the blade, so that the blade in the impeller is prevented from corrosion of cavitation under high-speed running, and the blade is prevented from wear, damage, destroy or bubbles due to solid particles during a running process.