Any unitary transformation can be decomposed into a product of a group of near-trivial transformations. We investigate in detail theconstruction of universal quantum circuit of near trivial transformations. We first construct two universal quantum circuits whichcan implement any single-qubit rotation Ry(θ) and Rz(θ) within any given precision, and then we construct universal quantum circuitimplementing any single-qubit transformation within any given precision. Finally, a universal quantum circuit implementing anyn-qubit near-trivial transformation is constructed using the universal quantum circuits of Ry(θ) and Rz(θ). In the universal quantumcircuit presented, each quantum transformation is encoded to a bit string which is used as ancillary inputs. The output of the circuitconsists of the related bit string and the result of near-trivial transformation. Our result may be useful for the design of universalquantum computer in the future.
