The invention discloses a method for efficiently evaluating the safety of a medicine in an hERG channel, characterized by firstly conducting routine culture of a cell strain expressing the hERG channel, then removing the culture medium and adding the cell strain into a fixed buffer, incubating for 1-4h under the routine culture conditions of the cell strain, removing the fixed buffer, then adding a fixed buffer containing the medicine to be evaluated and incubating for 5-40min, and then removing the fixed buffer containing the medicine to be evaluated, washing the cell strain by using a washing buffer to remove residual Rb+, adding an ion channel opening buffer and incubating for 5-20 min, removing the cell supernatant, cracking the cell strain into a cell lysate, and respectively determining the Rb+ concentrations in the cell supernatant and cell lysate; setting different concentrations of the medicine to be evaluated in the fixed buffer containing the medicine to be evaluated to repeatedly determine, acquiring an IC50 value according to obtained data of the determination of the medicine to be evaluated with different concentrations, wherein if the IC50 value is no larger than 1000 mumol/L, the medicine to be evaluated has a certain inhibition on the hERG channel, and the lower the IC50 value is, the higher the inhibition is and the larger the risk of cardiotoxicity is.