A practical multifunctional connection box for on-site wire connection is disclosed and comprises a box body; the front side of the box body is provided with three wire connecting columns that are respectively a live wire connecting column, a zero wire connecting column and a ground wire connecting column; the left side of the right side of the box body is provided with a concealed groove, and a three-hole plug head and a two-hole plug head are arranged in the concealed groove; one side face, provided with the concealed groove, of the box body is also provided with a slide way; a sling cover plate is connected in the slide way in a sliding manner, and the sliding cover plate is arranged outside the concealed groove. The practical multifunctional connection box can realize and is suitable for power source wire connection and signal wire connection in complex on-site test environment, almost all actual requirements for on-site work can be satisfied, simple and reliable wire connection can be realized, labor and time can be saved, and working efficiency can be greatly improved.