本論文是關於低成本可變焦內視鏡之研究。作為一項專業的檢測設備,內視鏡市售價相當昂貴。且現行內視鏡為了方便對各種狹小空間進行非破壞檢測,皆致力於尺寸微型化。因為已無足夠的空間加入變焦系統,所以內視鏡皆為定焦鏡頭設備。本論文利用7.5 mm管徑之平價USB訊號內視鏡,分別搭配市售電子式液體變焦透鏡及自製液體變焦透鏡,觀察並分析其應用效果,期望使用低成本讓內視鏡擁有變焦功能,也能擁有良好的成像品質。由實驗結果得知,自製液體變焦透鏡不僅價格低廉,分辨率數據也與商用電子式液體透鏡表現相當,可應用於空間狹小、接觸困難的部件執行檢查,並擁有清晰的影像,可謂理想的低成本可變焦內視鏡。;This paper mainly research about low cost varifocal endoscope. As a professional testing equipment, the price of endoscope is very expensive. And for easy to process non-destructive testing at various narrow space, all the endoscope manufacturer try to research and development their endoscope with smaller dimension. Because there is no more space to assemble zoom module, all the endoscopes are fix-focus lens device. This paper use cheap USB signal endoscope with 7.5 mm outer diameter, which is assemble with commercial electronic liquid lens and self-made liquid lens, observe and analyze their effects. Expecting to let the endoscope include zoom function and good image quality with low cost. According to the result, self-made liquid lens is not only inexpensive, but also has good visibility equivalent to comical liquid lens, it can be used to perform inspections on parts that have small space and difficult to contact, and has a good image quality. It is an ideal low cost varifocal endoscope.