The invention relates to the field of high-altitude meteorological detection, in particular to an L-band narrow-band electronic sonde, which is characterized by comprising a sensor module, a receivingmodule and a transmitting module, the transmitting module comprises a single-chip microcomputer control system, a multifunctional radio frequency module, a filter, a two-stage microwave switch, a two-stage high-frequency amplifier and a one-stage power amplifier. Sounding data of the sensor module and a pulse signal transmitted by the receiving module are input into the single-chip microcomputercontrol system; the single-chip microcomputer control system adopts a time-sharing working mode, divides unit time into three time periods and outputs sounding code signals, ranging signals and anglemeasurement signals respectively, and the signal characteristics are frequency modulation signals, pulse modulation signals and continuous wave signals respectively. According to the invention, a frequency modulation and amplitude modulation mixed system is adopted to solve the defects that the current amplitude modulation system sonde occupies a wide frequency band and the frequency modulation system sonde cannot measure the distance, and the requirement that meteorological frequency band spectrum resources occupy the bandwidth is met; and a time division working mode is adopted to solve same-frequency interference, and stability and reliability are achieved.