By means of the nonequilibrium Green’s function technique, influence of interdot hoppings t’s and intradot many-body interaction U on electronic transport through parallel triple-quantum-dot (tQD) device in the Coulomb blockade regime are theoretically investigated. In the symmetrical tQD device with uniform interdot hopping t, as t increases starting from zero, the conductance is enhanced due to the opening of new channels for the electronic transport, but as t increases over its critical tc, the interdot hoppings have an opposite influence, which are well consistent with those obtained by the numerical renormalization-group method. The effect of the intradot electron interaction U on the electronic transport through the tQD device is strongly relative to the strength of t. For small t, U suppresses the electronic transport and the Coulomb blockade effect on the dots is dominant. However, for relatively strong t, a small U has a contribution to enhance the electronic transport through the device. These theoretical results can be applied to explain the recent experimental findings on a parallel tQD device. In the asymmetrical parallel tQD device, the symmetry-breaking in the interdot hoppings leads to the increasing on the electronic transport owing to the appearance of more resonance levels in the conductance spectrum. On the basis of this feature, it is proposed that we can obtain some devices with desirable transport properties, such as the molecular charge rectifier, through adjusting the interdot hoppings and the intradot many-body interaction.