A dustproof cabinet-type computer apparatus comprises four foldable sections which can be folded to define a regular quadrangular contour shape with a hollow column body part (800) and can be pivoted and unfolded into a linear segment shape, wherein each foldable section comprises a cabinet body part (80) and a server unit (81) arranged in the cabinet body part (80); a cooling air-blowing apparatus (82) to which an air conveying pipe (61) supplies air is arranged at the bottom of the hollow column body part (800); and the cooling air-blowing apparatus (82) comprises an annular cavity housing (15) which is provided with an air inlet nozzle (6) to be communicated with the air conveying pipe (61).