The invention discloses an automatic tuning type downhole wireless signal transmission system, which comprises a downhole sending module and a well mouth antenna, wherein the downhole sending module is independently connected with a drilling tool and a logging-while-drilling tool in an oil pipe; the logging-while-drilling tool is placed on the drill bit of the drilling tool; the drilling tool comprises an insulated pup joint, wherein the insulated pup joint is laterally placed below a drilling tool motor and is positioned between the drill pipe and the drill collar of the drilling tool for realizing the electric isolation of the drill pipe and the drill collar; the positive pole of the downhole sending module is connected with one end, which is near the drill pipe, of the insulated pup joint; the negative pole of the downhole sending module is connected with one end, which is near the drill collar, of the insulated pup joint; the well mouth antenna is placed on a well mouth, one end isconnected with the oil pipe, and the other end is subjected to ground connection; the downhole sending module is adopted to receive logging-while-drilling data measured by the logging-while-drillingtool, a direct-driven way is adopted to convert the obtained logging-while-drilling data into an electric signal, and the electric signal is transmitted to the well mouth antenna through the oil pipeafter the electric signal is subjected to automatic tuning amplification. The automatic tuning type downhole wireless signal transmission system carries out transmission through the direct-driven way,and transmission efficiency is high.