The invention discloses a construction electric saw comprising a saw blade made from alloy steel, wherein one end of the saw blade is connected with an electric controller, the electric controller is internally provided with an electric motor, one side of the electric motor is connected with a telescopic shaft, the telescopic shaft is internally provided with a spring, and the upper side of the saw blade is provided with sawteeth. The construction electric saw has the advantages that the structure is simple, convenience is brought in the manufacture, the construction electric saw can be used in construction, convenience is brought in sawing materials under construction, and the sawteeth are not easy to break, so that the service life of the construction electric saw is prolonged; the degree of automation is high, flexibility and convenience are brought in operation, and the design is novel, therefore the construction electric saw is an excellent innovation scheme, and the market promotion prospect is good; and the construction electric saw is an excellent innovation scheme and is beneficial to the popularization and the usage.