Abstract: In order to solve the problem of low imaging resolution and high cost of the terahertz near-field sensor, a high image resolution and high integration sensor is proposed. The 330 GHz sensor is simulated based on a 55 nm complementary metal oxide semiconductor(CMOS) fabrication process. The sensor consists of a 330-336 GHz single-ended ring oscillators, a wideband resonator and a power detector and all of them are integrated on a single chip. The simulation results show that the ring oscillator reaches a peak output power of 0.9 dBm@330 GHz, which is 1.23 mW, at a bias of 2 V. According to the tuning range of the oscillator, a wideband resonator is designed for near-field sensing of the object. After placing objects with different dielectric permittivity on the top surface of the resonator, we connect the resonator to a detector to achieve a voltage output signal. The difference of this voltage and the voltage without an object on the resonator's surface is the response of the sensor. This monolithically integrated sensor has huge potential in the future of terahertz near-field imaging.