"等径孔道" can be translated as "uniform-diameter channel" or "constant-diameter pore" in English, depending on the specific context and the field in which it is used (e.g., materials science, chemistry, engineering).
"Uniform-diameter channel" emphasizes that the diameter of the channel remains consistent throughout its length.
"Constant-diameter pore" is more commonly used in contexts related to porous materials or membranes, where "pore" refers to a small opening or hole.