A new compression algorithm(DTAC) based on double threshold alternating is presented.According to the significant coefficient distribution on different thresholds based on integer wavelet transform(IWT),the new algorithm uses the integer square as the quantization thresholds instead of the integer powers of two(IPT) on the field where the significant coefficients concentrate relatively.However,the IPT are reserved as the quantization thresholds of other threshold planes.On every threshold plane,the single encoding strategy is applied for the significant coefficients.Experiment results show that the new algorithm can lower the coding complexity,support the remote sensing image compression using a single bitstream from lossy to lossless,and provide PSNR performance better than SPECK algorithm using the same IWT.