The invention relates to a line-marking device, in particular to a multi-functional line-marking vehicle for construction of a building site. Only one worker can perform operation. A paint storage device can greatly reduce time spent on adding paints. The sprays are sprayed out of a nozzle in the form of mist. Movable devices are installed on a total framework of a vehicle body. An air inflating device installing seat is installed on the total framework of the vehicle body. An air inflating device is installed on the air inflating device installing seat. A check valve is installed on the air inflating device. The paint storage device is installed on the total framework of the vehicle body. An air inlet connecting pipe is installed on the paint storage device. A paint stirring device is installed on the paint storage device, a sealing cover of which is installed on the paint storage device. A push armrest is installed on the total framework of the vehicle body. A pipe-joint bend is installed on a connection opening of the paint storage device. An upper end connection bent pipe is installed on the pipe-joint bend. A paint passing device is installed on the total framework of the vehicle body. A paint spray device is installed on the total framework of the vehicle body.