A twin-clutch type hybrid transmission is configured to include an input shaft 10, an odd-numbered stage shift mechanism 30, an even-numbered stage shift mechanism 60, a motor power mechanism 20, and an output mechanism 90. The shift mechanisms 30 and 60 include transmission gear trains 32 and 62, and main clutches 34 and 64, respectively, the main clutches 34 and 64 for selectively transmitting the power of the transmission gear train 32 and the power of the transmission gear train 62 to transmission shafts 40 and 70, respectively. The shift mechanisms 30 and 60 also include shift gear trains 41, 43, 45, 47, 72, 74, 76, and 78 provided to the transmission shafts 40 and 70 to transmit rotation to the output mechanism 90, respectively, and mechanical clutches 50, 52, 80, and 82 for selectively engaging the corresponding shift gear trains and the transmission shafts 40 and 70, respectively. As a result, a compact twin-clutch type hybrid transmission having high transmission efficiency can be obtained.