The quickest way to confirm the diagnosis of pericardial effusion is by echocardiography, which is simple, easy to perform, quick and reliable in diagnosing pericardial effusion. Pericardial effusion can be produced by various etiologies of pericarditis, the most common causes are tumor, idiopathic pericarditis and renal failure, in addition to severe circulation stasis, puncture wounds, ventricular rupture and so on, which can cause pericardial effusion, and the clinical characteristics of Beck’s triad: low blood pressure, weak heart sounds, and jugular venous rage. The X-ray of pericardial effusion is that the heart shadow is enlarged to both sides in the shape of a flask, the heart beat is weakened or disappeared, and the lung field is clear; the electrocardiogram shows that the QRS of the limb leads is low voltage, and when there is a large amount of effusion, the P-wave, QRS-wave, and T-wave can be seen to be alternating, which is often accompanied by sinus tachycardia; the diagnosis of pericardial effusion is simple and easy to carry out, rapid and reliable; the pericardiocentesis can improve the symptom and find out the cause of the disease. If you have pericardial effusion, please go to the hospital as soon as possible to identify the cause of the disease and target treatment to avoid delay.