A double moiré superlattice can be realized by stacking three layers of atomically thin two-dimensional materials with designer interlayer twisting or lattice mismatches. In this novel structure, atomic reconstruction of constituent layers could introduce significant modifications to  the lattice symmetry and electronic structure at small twist angles. Here, we employ conductive  atomic force microscopy (cAFM) to investigate symmetry breaking and local electrical properties  in twisted trilayer graphene. We observe clear double moiré superlattices with two distinct moiré  periods all over the sample. At neighboring domains of the large moiré, the current exhibit either  two- or six-fold rotational symmetry, indicating delicate symmetry breaking beyond the rigid  model. Moreover, an anomalous current appears at the ‘A-A’ stacking site of the larger moiré,  contradictory to previous observations on twisted bilayer graphene. Both behaviors can be  understood by atomic reconstruction, and we also show that the cAFM signal of twisted graphene  samples is dominated by the tip-graphene contact resistance that maps the local work function of  twisted graphene and the metallic tip qualitatively. Our results unveil cAFM is an effective probe  for visualizing atomic reconstruction and symmetry breaking in novel moiré superlattices, which  could provide new insights for exploring and manipulating more exotic quantum states based on  twisted van der Waals heterostructures.