A connecting device for motor and supply network is provided, comprising: a Variable Frequency Drive (VFD), a first switch (S1) and a second switch (S2), wherein the Variable Frequency Drive (VFD) is connected in series to the first switch (S1), and the second switch (S2) is connected in parallel to the series circuit composed of the Variable Frequency Drive (VFD) and the first switch (S1). The connecting device of the invention further comprises a bidirectional Silicon Controlled Rectifier (SCR) or two anti-parallel single-directional Silicon Controlled Rectifiers (SCR1,SCR2), wherein the bidirectional Silicon Controlled Rectifier (SCR) or the two anti-parallel single-directional Silicon Controlled Rectifiers (SCR1,SCR2) is/are connected in parallel to the second switch (S2). The connecting device of the present invention would not be subject to high current surge when VFD bypassing, avoids the high cost for the overrating of the cable and the bypassing switch, and is easy to be implemented.