An ultrasound-based handheld animal and plant tissue ablation instrument, comprising a handheld housing and an ultrasonic vibrator; wherein the housing comprises a first section and a second section, wherein the first section and the second section are disposed at an obtuse angle to each other; an end of the first section is away from the second section, and the end of the first section is the front end of the housing and wherein the ultrasonic vibrator comprises an ultrasonic transducer; the instrument being characterized in that the housing is internally provided with a control board and a drive board; the ultrasonic vibrator is fixedly connected to a front end of the housing and comprises an amplitude transformer, wherein the amplitude transformer is fixedly connected to a front end of the ultrasonic transducer, is configured to change an amplitude of vibration input by the ultrasonic transducer and to transmit out the vibration; the control board is provided with a power supply, a direct current to direct current, DCDC, conversion unit, a main control unit, a DCDC power adjustment unit and a sampling unit; the drive board is provided with a drive unit, a transformer unit and a resonance unit; a voltage of the power supply is converted through the DCDC conversion unit and the DCDC power adjustment unit and then is supplied to the ultrasound-based handheld animal and plant tissue ablation instrument; the main control unit outputs a first pulse width modulation, PWM, signal to control the DCDC power adjustment unit to output an adjustable voltage, and outputs two second PWM signals with complementary duty cycles to the drive unit based on feedback from the sampling unit, wherein the sampling unit acquires a voltage and a current of an output circuit of the transformer unit, the transformer unit transforms the voltage, and then the resonance unit arranged in the output circuit of the transformer unit adjusts a resonance point to a resonance point of the ultrasonic vibrator, so that the ultrasonic vibrator arranged in the output circuit of the transformer unit operates in a resonance state. comprising a handheld housing and an ultrasonic vibrator; wherein the housing comprises a first section and a second section, wherein the first section and the second section are disposed at an obtuse angle to each other; an end of the first section is away from the second section, and the end of the first section is the front end of the housing and wherein the ultrasonic vibrator comprises an ultrasonic transducer; the instrument being characterized in that the housing is internally provided with a control board and a drive board; the ultrasonic vibrator is fixedly connected to a front end of the housing and comprises an amplitude transformer, wherein the amplitude transformer is fixedly connected to a front end of the ultrasonic transducer, is configured to change an amplitude of vibration input by the ultrasonic transducer and to transmit out the vibration; the control board is provided with a power supply, a direct current to direct current, DCDC, conversion unit, a main control unit, a DCDC power adjustment unit and a sampling unit; the drive board is provided with a drive unit, a transformer unit and a resonance unit; a voltage of the power supply is converted through the DCDC conversion unit and the DCDC power adjustment unit and then is supplied to the ultrasound-based handheld animal and plant tissue ablation instrument; the main control unit outputs a first pulse width modulation, PWM, signal to control the DCDC power adjustment unit to output an adjustable voltage, and outputs two second PWM signals with complementary duty cycles to the drive unit based on feedback from the sampling unit, wherein the sampling unit acquires a voltage and a current of an output circuit of the transformer unit, the transformer unit transforms the voltage, and then the resonance unit arranged in the output circuit of the transformer unit adjusts a resonance point to a resonance point of the ultrasonic vibrator, so that the ultrasonic vibrator arranged in the output circuit of the transformer unit operates in a resonance state.