Semi-trailer is a large-scale cargo transport vehicle. With the improvement of traffic conditions, the transportation cost is gradually reduced. Operating semi-trailer can indeed earn a good income, but it can earn about 1, to 2, at most. If you drive your own car, the net profit for one year is between 1, and 15,. If the semi-trailer is newly bought and has a loan, it will not make much money. Because the cost of semi-trailer is also quite a lot, mainly including vehicle insurance cost, normal maintenance cost and maintenance cost.

a semi-trailer is a trailer whose axle is placed behind the center of gravity of the vehicle (when the vehicle is uniformly loaded) and is equipped with a coupling device that can transmit horizontal and vertical forces to the tractor. Semi-trailer is generally a three-axle semi-trailer, and its types are divided into eleven-meter barn semi-trailer, thirteen-meter barn semi-trailer, low-flat semi-trailer and many other types. It is a heavy transport vehicle connected with the semi-trailer head through a traction pin.