Same-tower mixing voltage multi-loop optical cable system and optical fiber fusion method thereof

The invention discloses a same-tower mixing voltage multi-loop optical cable system. The same-tower mixing voltage multi-loop optical cable system comprises a first transformer substation, a second transformer substation, a third transformer substation, a first optical cable, a second optical cable, a pole tower and a first contact box. The same-tower mixing voltage multi-loop optical cable system is characterized by further comprising a third optical cable, a fourth optical cable and a second contact box, the fifth end and the second end are connected in the first contact box, the eighth end is connected with the third transformer substation, and the sixth end and the seventh end are connected in the second contact box in a fusion mode. The invention further discloses an optical fiber fusion method. By means of the same-tower mixing voltage multi-loop optical cable system and the optical fiber fusion method, when a long-range project is constructed, circuits put into operation in the earlier stage do not nee