The invention relates to a portable grounding wire for a test. The portable grounding wire comprises a special grounding main wire, the left end of the special grounding main wire is connected with a grounding fixture and winds around a spool, the right section of the special grounding main wire is pulled out by the spool, a bare copper wire section is reserved at the right section of the special grounding main wire close to the end, the right end of the special grounding main wire is divided into three equipment grounding branch wires, ends of the three equipment grounding branch wires are respectively and fixedly connected with a standard general plug, the bare copper wire section is provided with a connection fixture electrically connected with the bare copper wire section, and the connection fixture is connected with three standby standard general plugs via three standby equipment grounding wires. According to the portable grounding wire, the requirement of multiple grounding points of different equipment and test apparatuses can be satisfied by one special grounding wire, the carrying of the special grounding wire is convenient, the usage is simple, various plugs can be replaced at the branch ends, the dimension requirements of different apparatuses and different ports can be met, convenience and rapidness are realized, and the test efficiency is improved.