The invention discloses a multifunctional water sample in-situ collection device comprising two parts: an external integral body and an internal control part. The external integral body consists of ahollow column, a water container, scales and the like. The multifunctional water sample in-situ collection device is in a cuboid shape. Besides, the collection device also includes a control circuit.The control circuit is composed of a floating contact switch arranged in a container, an indicating lamp arranged at the top of a sealing cover, a first power supply arranged in the sealing cover, anda power line I and a power line II, wherein the power line I and the power line II penetrate the hollow column. A positive electrode and a negative electrode of the indicating lamp are electrically connected with one end of the power line I and one end of the power line II respectively; and the other ends of the power line I and the power line II extend into the container through the hollow column. According to the invention, a closed loop is formed by the floating contact switch, the indicating lamp, the first power supply, the power line I and the power line II and thus the user is remindedof reaching of the maximum capacity of the column body by the water sample in the container, so that sampling is ended and great convenience is provided for the user.