<p>This paper presents a novel combined cycle propulsion scheme based on parallel combustion. The parallel combustion cycle engine (PCCE) comprises turbine engine components that form an internal bypass flow path, an outer combustor of parallel combustion set up in the external bypass, and an intake adjustment device set up in the intake to regulate the air input of the internal and external bypasses. Furthermore, a shunt adjustment body is installed at the outlet of the internal bypass compressor, which allows a portion of the high-pressure airflow compressed by the compressor to be diverted into the outer combustor. This can be utilized in the propulsion system of <i>Ma</i>0–7 wide-speed range flight vehicle. The paper constructs the principle structure of PCCE, describes the four operating modes and its working principle, and establishes its ideal thermodynamic cycle process. The results of the thermodynamic cycle analysis demonstrate that the PCCE in dual-combustion mode (<i>Ma</i>0.7–2) exhibits a broader speed range and higher thermal efficiency. In the transition mode (<i>Ma</i>2–4), the shunt adjustment body facilitates the utilization of compressed air to enhance specific thrust at <i>Ma</i>2.5 by 2.1% and at <i>Ma</i>3.2 by 5.8% in comparison to the over–under TBCC engine.</p>