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To predict the trafficability of pin-jointed box road equipments, the main structures of pin-jointed box road equipments and the corresponding terramechanics behavior were discussed. The equipments were simulated as pin-jointed rigid systems and the elastic foundation beam model was adopted to simulate the interaction mechanism between the structure and soil. Thus the sinkage influence line and the maximum sinkage under concentrated loading and distributed loading was calculated. The motion resistance due to the compaction of soils was estimated. The thrust of vehicles was decided by the adhesive coefficient between vehicles and metal plates that could be changed greatly if the road was sludgy. Then the drawbar-pull coefficients, varying deformation coefficients, adhesive coefficients and dimensions of road elements were discussed. It's concluded that the trafficability of pin-jointed box road equipments is well if the deformation coefficient is larger than 50 kN/m3, the adhesive coefficient is larger than 0.2 and the length of box elements is large than 2 m.