The invention discloses a soil sampling device for constructional engineering, and the device comprises a protection box, a positioning box, a sampling pipe, a lubricating mechanism, a dismounting mechanism and a damping mechanism; a motor is fixedly mounted in an inner cavity of the protection box, a driving shaft is arranged at one end of the motor, the driving shaft penetrates through the surface of the bottom end of the protection box, and the lubricating mechanism comprises a sleeve. According to the invention, through the arrangement of the sleeve, the long-time rotation friction force increase of the driving shaft on the motor at the bottom end of the protection box is effectively avoided, so a certain lubricating effect is achieved, the rotating efficiency of the driving shaft is improved, and the working efficiency of the device is further improved; through the arrangement of the pull handle, the problem that when the sampling pipe is damaged after long-time use and needs to be replaced, the dismounting process is tedious is effectively avoided, manpower is saved, the dismounting efficiency of the device is improved; through the arranged rubber columns, the situation thatvibration of the device cannot be buffered during working is effectively avoided, the stability of the device is improved, and the positioning accuracy of the device is guaranteed.