Based on the parameters of posterior distribution of bit error rate (BER) regarding parity check-Hamming correction protocol, the BER and its confidence interval of the remaining quantum keys were directly estimated. In experiment, instead of the raw quantum keys, two pseudo-random binary sequences were used which have the length of 1.4×10－7 and the BER follow binomial distribution. The error correction process utilizes the parity code and Hamming code for error detection correction respectively. The experimental results showed that when the initial bit error rate at 3% and 0.1%, by one time error detection and error correction, the BER falls to 2.47×10－3 and 1.43×10－7 respectively, when the confidence at 95%, the corresponding upper limit of BER at 2.77×10－3 and 10.57×10－7 respectively. These experimental results effectively assessed parity-Hamming error correction performance on the finite quantum keys, and provided reliable data for the post-processing in the quantum key distribution.