In this paper, a 0.5 volt, two-stage, pseudo-differential, high gain, and rail-to-rail bulk-driven operational transconductance amplifier (OTA) is presented. At the input stage, a new common-mode feedback method based on the cross-coupled structure is adopted with an output conductance stabilization circuit to overcome the gain variation brought by this new solution. At the output stage, a novel class-AB output circuit is proposed which makes full use of bulk terminals. This OTA is designed in 180nm CMOS technology. The DC gain and unit gain bandwidth are 71 dB and 5.7 MHz, respectively with phase margin of 51° under a capacitive load of 20 pF at the normal case. The average slew rate is 3.55 V/µs. Other simulation results also presented in detail which validates the proposed solution.