In the manufacturing process of nanometer time-grating sensor, the manufacturing errors caused by the processing technology are mainly manifested as the electrode geometric errors. By using the method of sectional area integral to build the mathematical model, the influence of electrode geometric errors on the measurement accuracy is analyzed in detail. It is revealed that there is an averaging effect when the signal is picked up by multiple induction electrodes, which can effectively homogenize the measurement errors caused by the random variation of electrode geometric errors. Two prototype sensors with a range of 200 mm are fabricated by micro-nano-machining technology with a manufacturing accuracy of 1 μm and printed circuit board (PCB) technology with a manufacturing accuracy of 10 μm, respectively. Accuracy comparison experiment is carried out and experimental results show that, due to the averaging effect, the prototype made by PCB technology has achieved a measurement accuracy of ±250 nm in the full range after simple linear compensation, which is close to the measurement accuracy of the prototype made by micro-nano-machining technology. Experimental results verify the effectiveness of the averaging effect of multiple induction electrodes.