The invention belongs to design methods of a volute of a centrifugal compressor, and particularly relates to an application of staggered spiral type design on volute. Spiral lines is designed as connecting lines of centers of each cross section of the volute, and the spiral lines spreads circumferentially from the volute. The volute is divided into 8-12 cross section positions circumferentially, central line of each cross section shifts 2-5mm along a shaft line with respect to the central line of the previous cross section, and a transverse volute tongue structure is formed. The transverse volute tongue is formed by means of shifting central lines of cross sections, and thus the volute is avoided from interfering with a chimney fan, an initial small cross section of the volute is protected, air is guided to flow, and efficiency is improved. The initial small cross section of the volute is protected by removing the small cross sections of 0-10 degrees, and thus flow is improved, and volute size is reduced. The volute chimney fan of the centrifugal compressor is smoothly connected with the volute which is designed in a staggered spiral method, initial shape line of the chimney fan is in accordance with air flow direction at the outlet of the volute, and impact loss is reduced.