A connector for electrical connection of a plurality of signal lines, comprising: a connector body having a connecting end and a wiring end having a plurality of holes in correspondence to said plurality of signal lines; a plurality of terminals disposed in the connector body, wherein each of the terminals has a terminal body extending from the connecting end to the wiring end and a piercing member formed at one end of the terminal body and disposed at the wiring end; and a rotary cable coupler having a plurality of plug holes corresponding to the piercing members for insertion of the signal lines and being provided with a line fastener having a plurality of fixing holes corresponding to the respective plug holes, wherein each of the piercing members has two spaced apart piercing blades extending perpendicular to the associated terminal body, a circumferential circular slot being formed between the two piercing blades, and said connector is configured such that, when the rotary cable coupler is rotated after the signal lines are inserted into the respective holes of the wiring end, the signal lines are pushed by the plug holes circularly towards the piercing members correspondingly such that the piercing members pierce the signal lines for the electrical connection, characterized in that said wiring end is a detachable, plate-shaped member, the holes of the wiring end being formed as through-holes, wherein each of the fixing holes is formed and surrounded by two hook portions oppositely spaced on the line fastener, wherein an embedded slot is formed between the two hook portions, the signal lines are inserted into the respective through-holes of the wiring end such as to protrude at least beyond the side surface of the wirting end, each of the piercing members extends perpendicular to the associated terminal body so as to be disposed close to a side surface of the wiring end, and the rotary coupler is configured such as to be sleeved around the wiring end. a connector body having a connecting end and a wiring end having a plurality of holes in correspondence to said plurality of signal lines; a plurality of terminals disposed in the connector body, wherein each of the terminals has a terminal body extending from the connecting end to the wiring end and a piercing member formed at one end of the terminal body and disposed at the wiring end; and a rotary cable coupler having a plurality of plug holes corresponding to the piercing members for insertion of the signal lines and being provided with a line fastener having a plurality of fixing holes corresponding to the respective plug holes, wherein each of the piercing members has two spaced apart piercing blades extending perpendicular to the associated terminal body, a circumferential circular slot being formed between the two piercing blades, and said connector is configured such that, when the rotary cable coupler is rotated after the signal lines are inserted into the respective holes of the wiring end, the signal lines are pushed by the plug holes circularly towards the piercing members correspondingly such that the piercing members pierce the signal lines for the electrical connection, characterized in that said wiring end is a detachable, plate-shaped member, the holes of the wiring end being formed as through-holes, wherein each of the fixing holes is formed and surrounded by two hook portions oppositely spaced on the line fastener, wherein an embedded slot is formed between the two hook portions, the signal lines are inserted into the respective through-holes of the wiring end such as to protrude at least beyond the side surface of the wirting end, each of the piercing members extends perpendicular to the associated terminal body so as to be disposed close to a side surface of the wiring end, and the rotary coupler is configured such as to be sleeved around the wiring end.