  The effects of different quantum feedback types on the estimation precision
of the detection efficiency are studied. It is found that the precision can be
more effective enhanced by a certain feedback type through comparing these
feedbacks and the precision has a positive relation with detection efficiency
for the optimal feedback when the system reach the state of dynamic balance. In
addition, the bigger the proportion of is the higher the precision is and we
will not obtain any information about the parameter to be estimated if is
chosen as initial state for the feedback type {\lambda}{\sigma}_z.
