  Multi-photon entanglement has been successfully made by experimental groups.
As the increase of photon number, several problems are encountered, say,
greater number of copies, longer time, the error of fidelity and so on. In this
paper, we present a new scheme based on Lagrange multiplier and feedback to
save the measure copies in multi-photon experiment and five percent of
measuring time, also guarantee the acceptable error of fidelity. All the
results have been supported by the data of eight photon experiment.
Furthermore, same approach is applied in the simulation for ten photon
entanglement, and 22.45 percent of copies are saved, optimized copy
distribution gives better estimation of fidelity than the average copy
distribution.
