conducted emission for smps
As said by Tony in his comment, you should increase the attenuation of the LC filter, however in the direction from the MOSFET to the AC mains: this means that \$L_2\$ and \$C_{64}\$ should be risen as much as possible. This measure could be sufficient, since the conducted emission from switching power supply is mainly a differential mode emission (it appears as two signals in phase opposition on the Line and Neutral conductors). Do not worry for the diodes, as they are seen as short circuits by the EMI conducted noise. To explain more precisely what I mean it is convenient to do a rough copy of your circuit, as I have done below:







simulate this circuit &ndash; Schematic created using CircuitLab

where


LISN is the LISN network needed for the conducted emission test, shown with the spectrum analyzer (or better the RF receiver) connected.
\$V_{AC}\$ is the voltage generator which models the power grid.


Modeling the \$Q_2\$ block as a square wave current generator and remembering that the diodes of a power supply bridge behave as low value resistors respect to the signals generated by the downstream circuitry (see Gray and Searle "Electronic Principles" Wiley, 1969), we have the following equivalent circuit:







simulate this circuit

where


\$Z_{Power Grid}\$ is the equivalent impedance of the power grid as seen fro the circuit input,
\$R_D\$ is the conducting diodes equivalent resistance


As you see, you have a circuit topology that resembles that of a \$\pi\$-filter: the only choice you have to make your circuit fit the conducting emission limits is to make this topology work for you, therefore you should try to rise \$L_2\$ and rise \$C_{64}\$ as much as possible, as already said.