  Currently, quantum computing is developing at a high speed because its high
parallelism and high computing power bring new solutions to many fields.
However, due to chip process technology, it is difficult to achieve full
coupling of all qubits on a quantum chip, so when compiling a quantum circuit
onto a physical chip, it is necessary to ensure that the two-qubit gate acts on
a pair of coupled qubits by inserting swap gates. It will cause great
additional cost when a large number of swap gates are inserted, leading to the
execution time of quantum circuits longer. In this paper, we designed a way
based on the business to insert swap gates BQA(Busy Qubits Avoid). We exploit
the imbalance of the number of gates on qubits, trying to hide the overhead of
swap gates. At the same time, we also expect swap gates to make as little
negative impact on subsequent two-qubit gates as possible. We have designed a
heuristic function that can take into account both of these points. Compared
with qiskit, the execution time of the circuit optimized by our proposed method
is only 0.5 times that of the qiskit compiled circuit. And when the number of
two-qubit gates is large, it will achieve higher level than general conditions.
This implies higher execution efficiency and lower decoherence error rate.
