Flow control using plasma actuator is a promising research field of aeronautical applications. Due to its low energy consumption, rapid response and simple construction, this actuator has been investigated in various aerodynamics problems, such as boundary layer flow control, drag reduction, lift enhancement, noise reduction, and flow separation control. In order to understand the controlling mechanism of plasma actuator, many researchers have been carried out some experiments on the plasma actuator characterization in quiescent air and obtained the evolution process of starting vortex induced by plasma actuator. But the plasma actuator always works under flow condition. Therefore, understanding the interaction process between the starting vortex and incoming flow is a key to promote this technology development. In this paper, the starting vortex induced by symmetrical Dielectric Barrier Discharge (DBD) plasma actuator in quiescent air or under flow condition was investigated using Particle Image Velocimetry (PIV). Compared with the asymmetrical DBD plasma actuator, the symmetrical plasma actuator adopted the whole metal plate model as the insulated electrode. Three layers of kapton film as dielectric material covered the testing model and the thickness of each layer was 0.05 mm. The copper foil which was 2 mm in width and 0.05 mm in thickness was mounted on the trailing edge of the plate and oriented along the spanwise direction to induce a wall jet in the streamwise direction. The input AC voltage was 8 kV p-p and the frequency of the power source was 3 kHz. The wind speed was 1 m/s. The results suggested that the symmetrical actuator produced one pair of counter-rotating starting vortexes on each side of upper electrode and the trajectory of the starting vortex core was shown to scale with t0.7 in quiescent air. Compared to the evolution law of starting vortex in still air, the development evolution and life time of starting vortex under flow condition was different due to the interaction influence between incoming flow and starting vortex. The breakdown time of downstream starting vortex was earlier and the location of the starting vortex core scaled with t0.45 under flow condition. Conversely, the life time of upstream starting vortex which was in the opposite direction of incoming flow was delayed. The incoming flow enhanced the upstream starting vortex’s capability of promoting mixing and entraining high-momentum fluid into boundary layer, therefore the boundary layer became more energetic and capable of withstanding adverse pressure gradient. The jet effect and mixing function could be achieved by the symmetrical plasma actuator. These investigations laid the groundwork for flow control using DBD plasma actuator at high wind speed or high Reynolds number.%为了进一步提高等离子体激励器控制能力，采用粒子图像测速仪技术，以介质阻挡放电等离子体激励器为研究对象，开展了有、无来流条件下等离子体诱导启动涡的实验研究，获得了来流对启动涡发展演化及生存时间的影响。与传统非对称布局介质阻挡放电等离子体激励器相比，本文采用整个平板金属模型作为植入电极的对称布局方式开展研究。在金属模型表面粘贴聚酰亚胺胶带作为绝缘介质。将铜箔作为暴露电极沿平板展向布置，使激励器诱导气流沿流向方向。研究结果表明：对称布局式激励器会在暴露电极两侧产生一对方向相反的启动涡。在顺流向方向，来流加速了启动涡的破碎；在逆来流方向，来流延长了启动涡的生存时间，从而增加了激励器的掺混能力。该布局激励器具有掺混及射流效应两种能力，为提高等离子体激励器在高风速或高雷诺数下的控制效果积累了技术基础。
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