Objective To design a microfluidic paper-based device and explore its qualitative detection capabilities for mercury, lead, aluminum, iron, and copper ions, as well as its detection capabilities in actual samples.Methods This study constructs a microfluidic paper-based device by combining five complexing reagents [ammonium aurintricarboxylate (ATA), dithizone (DZ), diphenylcarbazide (DPC), sodium diethyldithiocarbamate (DDTC), and eriochrome black T (EBT)] with masking agents. The reaction is tracked based on the Euclidean distance (ED) before and after the reaction.Results The target metal ions can cause obvious color changes in the paper-based device within a rapid response time of 10 s. Even in the presence of other common metal ions, this device still shows good selectivity. The paper-based device has the ability to detect in actual samples such as tap water, tea, and juice.Conclusion This device is characterized by simple preparation, portability, and a fast response. It can be used for qualitative detection of mercury, lead, aluminum, iron, and copper ions.