Abstract: With the continuous functional improvement of smart electric meters, switching power supplies show poor market competitiveness in the low-end electric meter market because they require a large number of peripheral components and have relatively high manufacturing costs. The traditional half-wave rectification resistance-capacitance step-down solution features simple peripheral circuits and low cost, yet it has obvious drawbacks including insufficient load capacity. Meanwhile, the design of two-channel anti-electricity-theft metering needs to install extra current transformers, which will further increase the overall cost. To satisfy both low-cost design targets and anti-electricity-theft metering requirements, this paper proposes a resistance-capacitance step-down circuit adopting dual-manganin two-channel metering and sampling structures. A "pseudo full-wave" circuit structure is introduced to greatly improve the load capacity of the power supply system. Component selection is completed through theoretical calculation analysis, and overall machine load capacity verification tests are carried out with simulation software and physical engineering prototypes. The test results indicate that the proposed design can provide stable continuous power supply for the management unit circuit, the main loop metering circuit and the auxiliary loop metering circuit. While maintaining the core low-cost advantage of the resistance-capacitance step-down topology, this design eliminates the need for current transformers, and delivers reliable load performance and anti-electricity-theft performance. Under full-load operating conditions, the output voltage ripple values of the three independent output channels remain at low levels: the management unit circuit has an output voltage of thirteen volts with an output ripple of sixteen millivolts; the main loop metering circuit has an output voltage of three point three volts with an output ripple of seventeen point six millivolts; the auxiliary loop metering circuit has an output voltage of three point three volts with an output ripple of sixteen point eight millivolts. The voltage ripple coefficient of the management unit circuit is zero point twelve percent, the voltage ripple coefficient of the main loop metering circuit is zero point fifty-three percent, and the voltage ripple coefficient of the auxiliary loop metering circuit is zero point fifty-one percent. All measured values meet the general industry specification that the output voltage ripple coefficient shall not exceed ten percent. In addition, the load capacity of this scheme is approximately fifty percent higher than that of the conventional half-wave resistance-capacitance step-down circuit, which makes the solution possess strong market competitiveness in the low-end smart electric meter industry.