The invention relates to a narrow channel for enhancing a fluid body turbulence effect with a passive mode. The width of a cross section of the channel is 6-20 mm, the height is 1-3 mm, and high roughness areas and low roughness areas are correspondingly arranged on the upper inner wall and the lower inner wall of the channel; and the high roughness areas and the low roughness areas are distributed at intervals of 45 degrees with the axis of the channel, and the strip distribution directions of the two opposite inner wall surfaces are orthogonal. The narrow channel for enhancing the fluid bodyturbulence effect with the passive mode has the beneficial effects that no translational or rotating component is used, so that the method is safe and reliable; the method for enhancing the fluid body turbulence effect with the passive mode is adopted, external auxiliary power is not needed, and only kinetic energy of the fluid body is used for enhancing the turbulence effect and the disturbanceinside the narrow channel; and the method can be applied to the fields of heat exchange, mixing, pipeline cleaning and the like of the narrow channel.