The utility model discloses a carbon-free obstacle avoiding walking dolly. The dolly independently moves on a plurality of 8-shaped track pile by pure mechanical control, and the dolly can adjust wheel base of front and rear wheels to adapt to changes of pile spacing while pile spacing changes. The overall structural feature design mainly comprises five aspects: dolly walking track design, design of an energy conversion mechanism, design of a transmission mechanism, design of a differential velocity mechanism, and design of a steering mechanism. Effects of the dolly are that structure is simple, starting performance is good, walking is smooth and steady, precision is high, energy utilization efficiency is high, so that practical teaching object can be completed by mechanical energy. The dolly is carbon-free, energy saving, and is environmentally friendly.