The present invention provides a synchronous mixing and conveying system of liquid, which comprises the following components: a plurality of containers while each container is provided with an overcurrent liquid discharging hole for restricting the liquid in the container to a specific capacity; a row of constant-volume liquid discharging holes while the overcurrent liquid discharging holes on the containers are provided at a same height and the constant-volume liquid discharging holes which are corresponding with one another on the containers are provided at a same height; a dispenser which comprises multiple branch pipes, is respectively connected with the constant-volume liquid discharging holes of each container and also comprises a liquid flow controller that is provided in at least one pipe but not provided in all pipes for controlling the liquid flow that flows downwards from the constant-volume liquid discharging holes of the container. The synchronous mixing and conveying system of liquid has a beneficial effect that the liquid, particularly the chemical composition can be correspondingly controlled according to a required proportion from the liquid flow.