As an indispensable part of modern encryption system, true random number generator (TRNG) plays a very important role in information security. A configurable, lightweight and high throughput true random number generator is presented. The structure uses NAND gates and XOR gates to form a configurable asynchronous feedback ring oscillator. By increasing the phase noise in a short time, the time jitter range is expanded, so as to improve the randomness of entropy source. The structure is tested and verified on Xilinx Kintex-7 for many times. The experimental results show that the proposed TRNG has strong robustness under the environmental changes of different temperatures (0 ℃ ~ 80 ℃ ) and different output voltages ( 0. 8 ~ 1. 2 V), and only consumes 43 LUTS and 6 DFFs in hardware resources, and obtains a throughput of up to 300 Mb / s. At the same time, the generated random bit stream can pass the NIST SP800-22 and NIST SP800-90B tests with high P values.