Method for sidetrack drilling of coiled tubing through oil pipe

The invention relates to a continuous pipe through oil pipe sidetrack drilling method which comprises the following steps that S1, when a crude oil pipe is reserved in an original shaft, a continuous pipe lower whipstock system penetrates through the crude oil pipe to lower a whipstock in the original shaft; when the crude oil pipe is not reserved in the original shaft, a whipstock is tripped into the original shaft by using a tubing string lower whipstock system; s2, after setting of the whipstock in the original shaft is completed, when a sidetrack drilling point is located in a casing well section of the original shaft, a continuous pipe is used for being connected with a windowing tool string to conduct windowing operation on the casing well section in the original shaft, and drilling testing operation continues after windowing operation is completed; when the sidetrack drilling point of the original shaft is located in the open hole well section, a continuous pipe is connected with a windowing tool strin